diff --git a/IRaCIS.Core.Application/Service/TrialSiteUser/TrialExternalUserService.cs b/IRaCIS.Core.Application/Service/TrialSiteUser/TrialExternalUserService.cs
index 26ea0bd3e..575572e50 100644
--- a/IRaCIS.Core.Application/Service/TrialSiteUser/TrialExternalUserService.cs
+++ b/IRaCIS.Core.Application/Service/TrialSiteUser/TrialExternalUserService.cs
@@ -322,7 +322,7 @@ namespace IRaCIS.Core.Application.Service
                 //收件地址
                 messageToSend.To.Add(new MailboxAddress(String.Empty, needUpdate.Email));
                 //主题
-                messageToSend.Subject = $"GRR External User survey (Trial {(editTrialUserPreparation.IsJoin == true ?"Reject Success":"Join Success")})";
+                messageToSend.Subject = $"GRR External User survey (Trial {(editTrialUserPreparation.IsJoin == false ?"Reject Success":"Join Success")})";
 
                 var builder = new BodyBuilder();
 
@@ -485,7 +485,7 @@ namespace IRaCIS.Core.Application.Service
                 //收件地址
                 messageToSend.To.Add(new MailboxAddress(String.Empty, needUpdate.Email));
                 //主题
-                messageToSend.Subject = $"GRR Site survey (Trial {(editInfo.IsJoin == true ?"Reject Success":"Join Success")})";
+                messageToSend.Subject = $"GRR Site survey (Trial {(editInfo.IsJoin == false ?"Reject Success":"Join Success")})";
 
                 var builder = new BodyBuilder();