diff --git a/IRaCIS.Core.Domain/Reading/ReadingPeriodSet.cs b/IRaCIS.Core.Domain/Reading/ReadingPeriodSet.cs
index 090198b6f..6f0549677 100644
--- a/IRaCIS.Core.Domain/Reading/ReadingPeriodSet.cs
+++ b/IRaCIS.Core.Domain/Reading/ReadingPeriodSet.cs
@@ -50,7 +50,7 @@ namespace IRaCIS.Core.Domain.Models
 		/// 访视模板
 		/// </summary>
 		[ForeignKey("VisitStageId")]
-		public VisitStage? VisitStage { get; set; }
+		public VisitStage VisitStage { get; set; }
     
 	    /// <summary>
 	    /// 是否生效