diff --git a/testable-core/src/main/java/com/alibaba/testable/core/util/ConstructionUtil.java b/testable-core/src/main/java/com/alibaba/testable/core/util/ConstructionUtil.java
index 7d049b4..7624fdb 100644
--- a/testable-core/src/main/java/com/alibaba/testable/core/util/ConstructionUtil.java
+++ b/testable-core/src/main/java/com/alibaba/testable/core/util/ConstructionUtil.java
@@ -18,31 +18,16 @@ public class ConstructionUtil {
     public static <T> T generateSubClassOf(Class<T> clazz) throws InstantiationException {
         StringBuilder sourceCode = new StringBuilder();
         sourceCode.append("package ").append(clazz.getPackage().getName()).append(";\n")
-                .append("public class ").append(getSubclassName(clazz))
-                .append(clazz.isInterface() ? " implements " : " extends ")
-                .append(getClassName(clazz))
-                .append(" {\n");
+                .append("public class ").append(getSubclassName(clazz));
+        appendTypeParameters(sourceCode, clazz.getTypeParameters(), true);
+        sourceCode.append(clazz.isInterface() ? " implements " : " extends ")
+                .append(getClassName(clazz));
+        appendTypeParameters(sourceCode, clazz.getTypeParameters(), false);
+        sourceCode.append(" {\n");
         for (Method m : clazz.getMethods()) {
             if (!Modifier.isStatic(m.getModifiers()) && !Modifier.isFinal(m.getModifiers())) {
                 sourceCode.append("\tpublic ");
-                TypeVariable<Method>[] typeParameters = m.getTypeParameters();
-                if (typeParameters.length > 0) {
-                    sourceCode.append("<");
-                    for (int i = 0; i < typeParameters.length; i++) {
-                        sourceCode.append(typeParameters[i].getName()).append(" extends ");
-                        Type[] bounds = typeParameters[i].getBounds();
-                        for (int j = 0; j < bounds.length; j++) {
-                            sourceCode.append(getClassName(bounds[j]));
-                            if (j < bounds.length - 1) {
-                                sourceCode.append(" & ");
-                            }
-                        }
-                        if (i < typeParameters.length - 1) {
-                            sourceCode.append(", ");
-                        }
-                    }
-                    sourceCode.append("> ");
-                }
+                appendTypeParameters(sourceCode, m.getTypeParameters(), true);
                 sourceCode.append(getClassName(m.getGenericReturnType())).append(" ")
                         .append(m.getName()).append("(");
                 Type[] parameters = m.getGenericParameterTypes();
@@ -75,6 +60,29 @@ public class ConstructionUtil {
         }
     }
 
+    private static void appendTypeParameters(StringBuilder sourceCode, TypeVariable<?>[] typeParameters, boolean withScope) {
+        if (typeParameters.length > 0) {
+            sourceCode.append("<");
+            for (int i = 0; i < typeParameters.length; i++) {
+                sourceCode.append(typeParameters[i].getName());
+                if (withScope) {
+                    sourceCode.append(" extends ");
+                    Type[] bounds = typeParameters[i].getBounds();
+                    for (int j = 0; j < bounds.length; j++) {
+                        sourceCode.append(getClassName(bounds[j]));
+                        if (j < bounds.length - 1) {
+                            sourceCode.append(" & ");
+                        }
+                    }
+                }
+                if (i < typeParameters.length - 1) {
+                    sourceCode.append(", ");
+                }
+            }
+            sourceCode.append("> ");
+        }
+    }
+
     private static String getClassName(Type clazz) {
         if (clazz instanceof Class) {
             return ((Class<?>)clazz).getName().replace(DOLLAR, DOT);
diff --git a/testable-core/src/test/java/com/alibaba/testable/core/util/ConstructionUtilTest.java b/testable-core/src/test/java/com/alibaba/testable/core/util/ConstructionUtilTest.java
index 8198527..de9ee30 100644
--- a/testable-core/src/test/java/com/alibaba/testable/core/util/ConstructionUtilTest.java
+++ b/testable-core/src/test/java/com/alibaba/testable/core/util/ConstructionUtilTest.java
@@ -36,15 +36,15 @@ class ConstructionUtilTest {
     public static abstract class AbstractClazz implements RealInterface {
         @Override
         public void noParameterMethod() {}
-        public abstract <T extends String> T getById(T id);
+        public abstract <T extends String> T getByName(T name);
         public abstract String getByTags(List<? extends String> tags);
         public static <T> T useless() { return null; }
     }
 
-    public static abstract class ParameterizedClazz<T> extends AbstractClazz implements RealInterface, EmptyInterface {
-        public abstract int getById(T id);
-        public abstract int getByIds(List<T> id);
-        public abstract int getByMap(Map<String, T> m);
+    public static abstract class ParameterizedClazz<S extends String, P> extends AbstractClazz implements RealInterface, EmptyInterface {
+        public abstract S getById(S id);
+        public abstract S getByIds(List<S> ids);
+        public abstract P getByMap(Map<String, P> m);
     }
 
     @Test