diff --git a/src/SmartSql/Configuration/Tags/PropertyChangedUtil.cs b/src/SmartSql/Configuration/Tags/PropertyChangedUtil.cs
index bc2d545c..a138e90a 100644
--- a/src/SmartSql/Configuration/Tags/PropertyChangedUtil.cs
+++ b/src/SmartSql/Configuration/Tags/PropertyChangedUtil.cs
@@ -1,7 +1,13 @@
+using System;
+using System.Xml;
+using SmartSql.Exceptions;
+
 namespace SmartSql.Configuration.Tags
 {
     public class PropertyChangedUtil
     {
+        private const String PROPERTY_CHANGED = nameof(IPropertyChanged.PropertyChanged);
+
         /// <summary>
         /// 验证属性值变更状态是否满足要求
         /// </summary>
@@ -40,5 +46,27 @@ public static bool IsCondition(IPropertyChanged propertyChanged, AbstractRequest
                 }
             }
         }
+
+        public static bool? GetPropertyChanged(XmlNode xmlNode, Statement statement)
+        {
+            string strVal = xmlNode.Attributes?[PROPERTY_CHANGED]?.Value?.Trim();
+            if (String.IsNullOrEmpty(strVal))
+            {
+                if (statement.EnablePropertyChangedTrack)
+                {
+                    return statement.EnablePropertyChangedTrack;
+                }
+
+                return null;
+            }
+
+            if (!Boolean.TryParse(strVal, out var boolVal))
+            {
+                throw new SmartSqlException($"can not convert {strVal} to Boolean from xml-node:{xmlNode.Value}.");
+            }
+
+            return boolVal;
+
+        }
     }
 }
\ No newline at end of file
diff --git a/src/SmartSql/Configuration/Tags/TagBuilders/AbstractTagBuilder.cs b/src/SmartSql/Configuration/Tags/TagBuilders/AbstractTagBuilder.cs
index bfb0cfb5..0fbeea23 100644
--- a/src/SmartSql/Configuration/Tags/TagBuilders/AbstractTagBuilder.cs
+++ b/src/SmartSql/Configuration/Tags/TagBuilders/AbstractTagBuilder.cs
@@ -8,7 +8,7 @@ namespace SmartSql.Configuration.Tags.TagBuilders
 {
     public abstract class AbstractTagBuilder : ITagBuilder
     {
-        private const String PROPERTY_CHANGED = nameof(IPropertyChanged.PropertyChanged);
+
         private const String PREPEND = nameof(Tag.Prepend);
         private const String PROPERTY = nameof(Tag.Property);
         private const String REQUIRED = nameof(Tag.Required);
@@ -33,32 +33,6 @@ public Decimal GetXmlAttributeValueAsDecimal(XmlNode xmlNode, string attributeNa
             return decimalVal;
         }
 
-        public bool TryGetXmlAttributeValueAsBool(XmlNode xmlNode, string attributeName, out bool boolVal)
-        {
-            string strVal = GetXmlAttributeValue(xmlNode, attributeName);
-            if (String.IsNullOrEmpty(strVal))
-            {
-                boolVal = false;
-                return false;
-            }
-
-            if (!Boolean.TryParse(strVal, out boolVal))
-            {
-                throw new SmartSqlException($"can not convert {strVal} to Boolean from xml-node:{xmlNode.Value}.");
-            }
-
-            return true;
-        }
-
-        public bool? GetPropertyChanged(XmlNode xmlNode)
-        {
-            if (TryGetXmlAttributeValueAsBool(xmlNode, PROPERTY_CHANGED, out var boolVal))
-            {
-                return boolVal;
-            }
-            return null;
-        }
-
         public String GetPrepend(XmlNode xmlNode)
         {
             return GetXmlAttributeValue(xmlNode, PREPEND);
diff --git a/src/SmartSql/Configuration/Tags/TagBuilders/IsPropertyBuilder.cs b/src/SmartSql/Configuration/Tags/TagBuilders/IsPropertyBuilder.cs
index 7a7d2bdc..7e896ae3 100644
--- a/src/SmartSql/Configuration/Tags/TagBuilders/IsPropertyBuilder.cs
+++ b/src/SmartSql/Configuration/Tags/TagBuilders/IsPropertyBuilder.cs
@@ -9,17 +9,12 @@ public class IsPropertyBuilder : AbstractTagBuilder
     {
         public override ITag Build(XmlNode xmlNode, Statement statement)
         {
-            var propertyChanged = GetPropertyChanged(xmlNode);
-            if (statement.EnablePropertyChangedTrack && !propertyChanged.HasValue)
-            {
-                propertyChanged = statement.EnablePropertyChangedTrack;
-            }
             return new IsProperty
             {
                 Property = GetProperty(xmlNode),
                 Prepend = GetPrepend(xmlNode),
                 ChildTags = new List<ITag>(),
-                PropertyChanged = propertyChanged,
+                PropertyChanged = PropertyChangedUtil.GetPropertyChanged(xmlNode, statement),
                 Statement = statement
             };
         }