diff --git a/sentinel-core/src/test/java/com/alibaba/csp/sentinel/node/ClusterNodeTest.java b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/node/ClusterNodeTest.java
new file mode 100644
index 00000000..e762a09f
--- /dev/null
+++ b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/node/ClusterNodeTest.java
@@ -0,0 +1,149 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.node;
+
+import com.alibaba.csp.sentinel.slots.block.flow.FlowException;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Random;
+import java.util.Set;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import static org.junit.Assert.*;
+
+/**
+ * Test cases for {@link ClusterNode}.
+ *
+ * @author cdfive
+ * @date 2019-01-11
+ */
+public class ClusterNodeTest {
+
+    @Test
+    public void testGetOrCreateOriginNodeSingleThread() {
+        ClusterNode clusterNode = new ClusterNode();
+
+        String origin1 = "origin1";
+        Node originNode1 = clusterNode.getOrCreateOriginNode(origin1);
+        assertNotNull(originNode1);
+        assertEquals(1, clusterNode.getOriginCountMap().size());
+
+        String origin2 = "origin2";
+        Node originNode2 = clusterNode.getOrCreateOriginNode(origin2);
+        assertNotNull(originNode2);
+        assertEquals(2, clusterNode.getOriginCountMap().size());
+        assertNotSame(originNode1, originNode2);
+
+        // test same origin, no StatisticNode added into the originCountMap
+        Node tmpOriginNode = clusterNode.getOrCreateOriginNode(origin1);
+        assertEquals(2, clusterNode.getOriginCountMap().size());
+        assertSame(tmpOriginNode, originNode1);
+
+        assertTrue(clusterNode.getOriginCountMap().containsKey(origin1));
+        assertTrue(clusterNode.getOriginCountMap().containsKey(origin2));
+    }
+
+    @Test
+    public void testGetOrCreateOriginNodeMultiThread() {
+        // note: in junit4, repeat execute a test method is not very convenient
+        // for simple, here use a loop instead
+        // https://stackoverflow.com/questions/1492856/easy-way-of-running-the-same-junit-test-over-and-over
+        // in junit5, use @RepeatedTest(10)
+        int testTimes = 10;// execute 10 times, test will have chance to failed, if remove the lock in ClusterNode
+        for (int times = 0; times < testTimes; times++) {
+            final ClusterNode clusterNode = new ClusterNode();
+
+            // store all distinct nodes by calling ClusterNode#getOrCreateOriginNode
+            final Set<Node> createdNodes = new HashSet<Node>();
+
+            final Random random = new Random();
+
+            // 10 threads, 3 origins, 20 tasks(in total, calling 20 times of ClusterNode#getOrCreateOriginNode concurrently)
+            final ExecutorService es = Executors.newFixedThreadPool(10);
+            final List<String> origins = Arrays.asList("origin1", "origin2", "origin3");
+            int taskCount = 20;
+
+            List<Callable<Object>> tasks = new ArrayList<Callable<Object>>(taskCount);
+            for (int i = 0; i < taskCount; i++) {
+                tasks.add(new Callable<Object>() {
+                    @Override
+                    public Object call() throws Exception {
+                        // one task call one times of ClusterNode#getOrCreateOriginNode
+                        Node node = clusterNode.getOrCreateOriginNode(origins.get(random.nextInt(origins.size())));
+                        // add the result node to the createdNodes set
+                        // node: since HashSet is non-threadsafe, synchronized the ClusterNodeTest.class
+                        synchronized (ClusterNodeTest.class) {
+                            createdNodes.add(node);
+                        }
+                        return null;
+                    }
+                });
+            }
+
+            try {
+                es.invokeAll(tasks);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+            es.shutdown();
+
+            // origins.size() origins, the same count as the originCountMap
+            assertEquals(origins.size(), clusterNode.getOriginCountMap().size());
+
+            // not use `assertEquals(origins.size(), createdNodes.size());`, but a compare judgement for debug
+            if (origins.size() != createdNodes.size()) {
+                // for debug, we can add a breakpoint here to see the detail info of createdNodes, if remove the lock in ClusterNode
+                fail("originCountMap's size should " + origins.size() + ", but actual " + createdNodes.size());
+            }
+
+            // verify originCountMap's key
+            for (String origin : origins) {
+                assertTrue(clusterNode.getOriginCountMap().containsKey(origin));
+            }
+        }
+    }
+
+
+    @Test
+    public void testTrace() {
+        ClusterNode clusterNode = new ClusterNode();
+
+        Exception exception = new RuntimeException("test");
+
+        // test count<=0, no exceptionQps added
+        clusterNode.trace(exception, 0);
+        clusterNode.trace(exception, -1);
+        assertEquals(0, clusterNode.exceptionQps());
+        assertEquals(0, clusterNode.totalException());
+
+        // test count=1, not BlockException, 1 exceptionQps added
+        clusterNode.trace(exception, 1);
+        assertEquals(1, clusterNode.exceptionQps());
+        assertEquals(1, clusterNode.totalException());
+
+        // test count=1, BlockException, no exceptionQps added
+        FlowException flowException = new FlowException("flow");
+        clusterNode.trace(flowException, 1);
+        assertEquals(1, clusterNode.exceptionQps());
+        assertEquals(1, clusterNode.totalException());
+    }
+}
diff --git a/sentinel-core/src/test/java/com/alibaba/csp/sentinel/node/DefaultNodeBuilderTest.java b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/node/DefaultNodeBuilderTest.java
new file mode 100644
index 00000000..19eb927b
--- /dev/null
+++ b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/node/DefaultNodeBuilderTest.java
@@ -0,0 +1,85 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.node;
+
+import com.alibaba.csp.sentinel.EntryType;
+import com.alibaba.csp.sentinel.slotchain.ResourceWrapper;
+import com.alibaba.csp.sentinel.slotchain.StringResourceWrapper;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Test cases for {@link DefaultNodeBuilder}.
+ *
+ * @author cdfive
+ * @date 2019-01-15
+ */
+public class DefaultNodeBuilderTest {
+
+    @Test
+    public void testBuildTreeNode() {
+        DefaultNodeBuilder builder = new DefaultNodeBuilder();
+
+        ResourceWrapper id = new StringResourceWrapper("resA", EntryType.IN);
+        ClusterNode clusterNode = new ClusterNode();
+        DefaultNode defaultNode = builder.buildTreeNode(id, clusterNode);
+
+        assertNotNull(defaultNode);
+        assertEquals(id, defaultNode.getId());
+        assertEquals(clusterNode, defaultNode.getClusterNode());
+
+        // verify each call returns a different instance
+        DefaultNode defaultNode2 = builder.buildTreeNode(id, clusterNode);
+        assertNotNull(defaultNode2);
+        assertNotSame(defaultNode, defaultNode2);
+        // now DefaultNode#equals(Object) is not implemented, they are not equal
+        assertNotEquals(defaultNode, defaultNode2);
+    }
+
+    @Test
+    public void testBuildTreeNode_NullClusterNode() {
+        DefaultNodeBuilder builder = new DefaultNodeBuilder();
+
+        ResourceWrapper id = new StringResourceWrapper("resA", EntryType.IN);
+        DefaultNode defaultNode = builder.buildTreeNode(id, null);
+
+        assertNotNull(defaultNode);
+        assertEquals(id, defaultNode.getId());
+        assertEquals(null, defaultNode.getClusterNode());
+
+        // verify each call returns a different instance
+        DefaultNode defaultNode2 = builder.buildTreeNode(id, null);
+        assertNotNull(defaultNode2);
+        assertNotSame(defaultNode, defaultNode2);
+        // now DefaultNode#equals(Object) is not implemented, they are not equal
+        assertNotEquals(defaultNode, defaultNode2);
+    }
+
+    @Test
+    public void testBuildClusterNode() {
+        DefaultNodeBuilder builder = new DefaultNodeBuilder();
+        ClusterNode clusterNode = builder.buildClusterNode();
+        assertNotNull(clusterNode);
+
+        // verify each call returns a different instance
+        ClusterNode clusterNode2 = builder.buildClusterNode();
+        assertNotNull(clusterNode2);
+        assertNotSame(clusterNode, clusterNode2);
+        // as new a ClusterNode instance in DefaultNodeBuilder#buildClusterNode(), they are not equal
+        assertNotEquals(clusterNode, clusterNode2);
+    }
+}
diff --git a/sentinel-core/src/test/java/com/alibaba/csp/sentinel/node/StatisticNodeTest.java b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/node/StatisticNodeTest.java
new file mode 100644
index 00000000..674985f8
--- /dev/null
+++ b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/node/StatisticNodeTest.java
@@ -0,0 +1,202 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.csp.sentinel.node;
+
+import com.alibaba.csp.sentinel.Constants;
+import com.alibaba.csp.sentinel.util.TimeUtil;
+import org.junit.Test;
+
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Test cases for {@link StatisticNode}.
+ *
+ * @author cdfive
+ * @date 2019-01-08
+ */
+public class StatisticNodeTest {
+
+    private static final String LOG_PREFIX = "[StatisticNodeTest]";
+
+    private static final SimpleDateFormat SDF = new SimpleDateFormat("yyyy-HH-dd HH:mm:ss");
+
+    private static final Random RANDOM = new Random();
+
+    private static final int THREAD_COUNT = 20;
+
+    /**
+     * A simple test for statistic threadNum and qps by using StatisticNode
+     *
+     * <p>
+     * 20 threads, 30 tasks, every task execute 10 times of bizMethod
+     * one bizMthod execute within 1 second, and within 0.5 second interval to exceute next bizMthod
+     * so that the total time cost will be within 1 minute
+     * </p>
+     *
+     * <p>
+     * Print the statistic info of StatisticNode and verify some results
+     * </p>
+     */
+    @Test
+    public void testStatisticThreadNumAndQps() {
+        long testStartTime = TimeUtil.currentTimeMillis();
+
+        int taskCount = 30;
+        int taskBizExecuteCount = 10;
+
+        StatisticNode node = new StatisticNode();
+
+        ExecutorService bizEs = Executors.newFixedThreadPool(THREAD_COUNT);
+        ExecutorService tickEs = Executors.newSingleThreadExecutor();
+
+        tickEs.submit(new TickTask(node));
+
+        List<BizTask> bizTasks = new ArrayList<BizTask>(taskBizExecuteCount);
+        for (int i = 0; i < taskCount; i++) {
+            bizTasks.add(new BizTask(node, taskBizExecuteCount));
+        }
+        try {
+            bizEs.invokeAll(bizTasks);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+
+        log("====================================================");
+        log("all biz task done, waiting 3 second to exit");
+        sleep(3000);
+
+        bizEs.shutdown();
+        tickEs.shutdown();
+
+        // now no biz method execute, so there is no curThreadNum,passQps,successQps
+        assertEquals(0, node.curThreadNum());
+        assertEquals(0, node.passQps());
+        assertEquals(0, node.successQps());
+
+        // note: total time cost should be controlled within 1 minute,
+        // as the node.totalRequest() holding statistics of recent 60 seconds
+        int totalRequest = taskCount * taskBizExecuteCount;
+        // verify totalRequest
+        assertEquals(totalRequest, node.totalRequest());
+        // as all execute success, totalRequest should equal to totalSuccess
+        assertEquals(totalRequest, node.totalSuccess());
+
+        // now there are no data in time span, so the minRT should be equals to TIME_DROP_VALVE
+        assertEquals(node.minRt(), Constants.TIME_DROP_VALVE);
+
+        log("====================================================");
+        log("testStatisticThreadNumAndQps done, cost " + (TimeUtil.currentTimeMillis() - testStartTime) + "ms");
+    }
+
+    private static class BizTask implements Callable<Object> {
+
+        private StatisticNode node;
+
+        private Integer bizExecuteCount;
+
+        public BizTask(StatisticNode node, Integer bizExecuteCount) {
+            this.node = node;
+            this.bizExecuteCount = bizExecuteCount;
+        }
+
+        @Override
+        public Object call() throws Exception {
+            while (true) {
+                node.increaseThreadNum();
+                node.addPassRequest(1);
+
+                long startTime = TimeUtil.currentTimeMillis();
+                bizMethod();
+
+                node.decreaseThreadNum();
+
+                // decrease one ThreadNum, so curThreadNum should less than THREAD_COUNT
+                assertTrue(node.curThreadNum() < THREAD_COUNT);
+
+                long rt = TimeUtil.currentTimeMillis() - startTime;
+                node.addRtAndSuccess(rt, 1);
+
+                // wait random 0.5 second for simulate method call interval,
+                // otherwise the curThreadNum will always be THREAD_COUNT at the beginning
+                sleep(RANDOM.nextInt(500));
+
+                bizExecuteCount--;
+                if (bizExecuteCount <= 0) {
+                    break;
+                }
+            }
+
+            return null;
+        }
+    }
+
+    private static void bizMethod() {
+        // simulate biz method call in random 1 second
+        sleep(RANDOM.nextInt(1000));
+    }
+
+    private static class TickTask implements Runnable {
+
+        private StatisticNode node;
+
+        public TickTask(StatisticNode node) {
+            this.node = node;
+        }
+
+        @Override
+        public void run() {
+            while (true) {
+                // print statistic info every 1 second
+                sleep(1000);
+
+                // the curThreadNum should not greater than THREAD_COUNT
+                assertTrue(node.curThreadNum() <= THREAD_COUNT);
+
+                logNode(node);
+            }
+        }
+    }
+
+    private static void sleep(long ms) {
+        try {
+            TimeUnit.MILLISECONDS.sleep(ms);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private static void logNode(StatisticNode node) {
+        log(SDF.format(new Date()) + " curThreadNum=" + node.curThreadNum() + ",passQps=" + node.passQps()
+                + ",successQps=" + node.successQps() + ",maxSuccessQps=" + node.maxSuccessQps()
+                + ",totalRequest=" + node.totalRequest() + ",totalSuccess=" + node.totalSuccess()
+                + ",avgRt=" + node.avgRt() + ",minRt=" + node.minRt());
+    }
+
+    private static void log(Object obj) {
+        System.out.println(LOG_PREFIX + obj);
+    }
+}