diff --git a/HealthMonitor.Service/Resolver/PregnancyHeartRateResolver.cs b/HealthMonitor.Service/Resolver/PregnancyHeartRateResolver.cs
index 5c088cc..8fca0a5 100644
--- a/HealthMonitor.Service/Resolver/PregnancyHeartRateResolver.cs
+++ b/HealthMonitor.Service/Resolver/PregnancyHeartRateResolver.cs
@@ -256,8 +256,8 @@ namespace HealthMonitor.Service.Resolver
                             HeartRate = fetalHeartRate,
                             SampleTime = sampleTime,
                             IsAbnormal = isAbnormal,
-                            StatStartTime = filteredPhr.OrderByDescending(i => i.LastUpdate).First().LastUpdate,
-                            StatEndTime = filteredPhr.OrderByDescending(i => i.LastUpdate).Last().LastUpdate,
+                            StatStartTime = filteredPhr.OrderBy(i => i.LastUpdate).First().LastUpdate,
+                            StatEndTime = filteredPhr.OrderBy(i => i.LastUpdate).Last().LastUpdate,
                             CreateTime = DateTime.Now,
                             Method = 1,
                             IsDisplay = 1,