diff --git a/core/src/main/java/com/alibaba/druid/sql/ast/statement/SQLMergeStatement.java b/core/src/main/java/com/alibaba/druid/sql/ast/statement/SQLMergeStatement.java
index 4059c49b11..3e8a873277 100644
--- a/core/src/main/java/com/alibaba/druid/sql/ast/statement/SQLMergeStatement.java
+++ b/core/src/main/java/com/alibaba/druid/sql/ast/statement/SQLMergeStatement.java
@@ -138,6 +138,21 @@ public WhenUpdate cloneTo() {
             cloneTo(x);
             return x;
         }
+
+        @Override
+        public boolean replace(SQLExpr expr, SQLExpr target) {
+            boolean isSuccess = false;
+            if (expr instanceof SQLUpdateSetItem && target instanceof SQLUpdateSetItem) {
+                for (int i = 0; i < items.size(); i++) {
+                    if (items.get(i) == expr) {
+                        target.setParent(this);
+                        items.set(i, (SQLUpdateSetItem) target);
+                        isSuccess = true;
+                    }
+                }
+            }
+            return isSuccess || super.replace(expr, target);
+        }
     }
 
     public static class WhenInsert extends When {
@@ -203,6 +218,27 @@ public WhenInsert cloneTo() {
             cloneTo(x);
             return x;
         }
+
+        @Override
+        public boolean replace(SQLExpr expr, SQLExpr target) {
+            boolean isSuccess = false;
+            for (int i = 0; i < columns.size(); i++) {
+                if (columns.get(i) == expr) {
+                    target.setParent(this);
+                    columns.set(i, target);
+                    isSuccess = true;
+                }
+            }
+
+            for (int i = 0; i < values.size(); i++) {
+                if (values.get(i) == expr) {
+                    target.setParent(this);
+                    values.set(i, target);
+                    isSuccess = true;
+                }
+            }
+            return isSuccess || super.replace(expr, target);
+        }
     }
 
     public static class WhenDelete extends When {
@@ -228,7 +264,7 @@ public WhenDelete cloneTo() {
         }
     }
 
-    public abstract static class When extends SQLObjectImpl {
+    public abstract static class When extends SQLObjectImpl implements SQLReplaceable {
         protected boolean not;
         protected SQLName by;
         protected SQLExpr where;
@@ -281,5 +317,14 @@ public void setWhere(SQLExpr x) {
             }
             this.where = x;
         }
+
+        public boolean replace(SQLExpr expr, SQLExpr target) {
+            if (this.where == expr) {
+                target.setParent(this);
+                this.where = target;
+                return true;
+            }
+            return false;
+        }
     }
 }
diff --git a/core/src/test/java/com/alibaba/druid/bvt/sql/ReplaceTest.java b/core/src/test/java/com/alibaba/druid/bvt/sql/ReplaceTest.java
new file mode 100644
index 0000000000..c08e50aff3
--- /dev/null
+++ b/core/src/test/java/com/alibaba/druid/bvt/sql/ReplaceTest.java
@@ -0,0 +1,28 @@
+package com.alibaba.druid.bvt.sql;
+
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
+import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
+import com.alibaba.druid.sql.ast.statement.SQLMergeStatement;
+import org.junit.Assert;
+import org.junit.Test;
+
+
+public class ReplaceTest {
+    @Test
+    public void test_when() {
+        SQLMergeStatement.WhenInsert when = new SQLMergeStatement.WhenInsert();
+        when.addColumn(new SQLIdentifierExpr("id"));
+        when.addColumn(new SQLIdentifierExpr("id2"));
+        SQLIdentifierExpr current_timestamp_identifier1 = new SQLIdentifierExpr("current_timestamp");
+        SQLIdentifierExpr current_timestamp_identifier2 = new SQLIdentifierExpr("current_timestamp");
+        when.addValue(current_timestamp_identifier1);
+        when.addValue(current_timestamp_identifier2);
+        SQLMethodInvokeExpr current_timestamp_method1 = new SQLMethodInvokeExpr("current_timestamp");
+        SQLMethodInvokeExpr current_timestamp_method2 = new SQLMethodInvokeExpr("current_timestamp");
+        SQLUtils.replaceInParent(current_timestamp_identifier1, current_timestamp_method1);
+        SQLUtils.replaceInParent(current_timestamp_identifier2, current_timestamp_method2);
+        Assert.assertEquals(current_timestamp_method1, when.getValues().get(0));
+        Assert.assertEquals(current_timestamp_method2, when.getValues().get(1));
+    }
+}