diff --git a/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/java/com/yomahub/liteflow/test/abstractChain/AbstractChainJsonELSpringBootTest.java b/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/java/com/yomahub/liteflow/test/abstractChain/AbstractChainJsonELSpringBootTest.java
index 63d25911c..38f2ea997 100644
--- a/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/java/com/yomahub/liteflow/test/abstractChain/AbstractChainJsonELSpringBootTest.java
+++ b/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/java/com/yomahub/liteflow/test/abstractChain/AbstractChainJsonELSpringBootTest.java
@@ -50,4 +50,11 @@ public class AbstractChainJsonELSpringBootTest extends BaseTest {
 		Assertions.assertEquals("a==>b==>a==>b==>a==>b==>f==>a==>b", response.getExecuteStepStrWithoutTime());
 	}
 
+	@Test
+	public void test4() throws Exception {
+		LiteflowResponse response = flowExecutor.execute2Resp("implD", "arg");
+		Assertions.assertTrue(response.isSuccess());
+		Assertions.assertEquals("a==>b==>j==>k==>c==>d==>f==>j", response.getExecuteStepStrWithoutTime());
+	}
+
 }
diff --git a/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/java/com/yomahub/liteflow/test/abstractChain/AbstractChainXmlELSpringbootTest.java b/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/java/com/yomahub/liteflow/test/abstractChain/AbstractChainXmlELSpringbootTest.java
index efc11bec2..8a6b52be7 100644
--- a/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/java/com/yomahub/liteflow/test/abstractChain/AbstractChainXmlELSpringbootTest.java
+++ b/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/java/com/yomahub/liteflow/test/abstractChain/AbstractChainXmlELSpringbootTest.java
@@ -52,4 +52,11 @@ public class AbstractChainXmlELSpringbootTest extends BaseTest {
 		Assertions.assertEquals("a==>b==>a==>b==>a==>b==>f==>a==>b", response.getExecuteStepStrWithoutTime());
 	}
 
+	@Test
+	public void test4() throws Exception {
+		LiteflowResponse response = flowExecutor.execute2Resp("implD", "arg");
+		Assertions.assertTrue(response.isSuccess());
+		Assertions.assertEquals("a==>b==>a==>b==>j==>k==>c==>d==>f==>j", response.getExecuteStepStrWithoutTime());
+	}
+
 }
diff --git a/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/resources/abstractChain/flow.el.xml b/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/resources/abstractChain/flow.el.xml
index e55fdc839..1b1ded112 100644
--- a/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/resources/abstractChain/flow.el.xml
+++ b/liteflow-testcase-el/liteflow-testcase-el-springboot/src/test/resources/abstractChain/flow.el.xml
@@ -6,7 +6,7 @@
     </chain>
 
     <chain id="implC" extends="base2">
-        {3}=THEN(a,b);
+        {3} = THEN(a,b);
         {4}=THEN(a,b).id("j");
     </chain>
 
@@ -23,4 +23,16 @@
         {0}=THEN(a,b,{3});
         {1}=SWITCH(f).to({4},k);
     </chain>
+
+    <chain abstract="true" name="base3">
+        THEN({_pre},{mainChain}, {subChain1},{subChain2},{end_chain})
+    </chain>
+
+    <chain extends="base3" id="implD">
+        {_pre} = THEN(a,b);
+        {mainChain}=THEN(a,b);
+        {subChain1}=THEN(j,k);
+        {subChain2}=IF(c, d, e);
+        {end_chain}=SWITCH(f).to(j,k);
+    </chain>
 </flow>
\ No newline at end of file