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 c99defe..1fcbc3f 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
@@ -5,7 +5,8 @@ import com.alibaba.testable.core.tool.OmniConstructor;
 
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
-import java.lang.reflect.Parameter;
+import java.lang.reflect.Type;
+import java.lang.reflect.TypeVariable;
 
 import static com.alibaba.testable.core.constant.ConstPool.DOLLAR;
 import static com.alibaba.testable.core.constant.ConstPool.DOT;
@@ -19,13 +20,32 @@ public class ConstructionUtil {
         sourceCode.append("package ").append(clazz.getPackage().getName()).append(";\n")
                 .append("public class ").append(getSubclassName(clazz))
                 .append(clazz.isInterface() ? " implements " : " extends ")
-                .append(clazz.getName().replace(DOLLAR, DOT))
+                .append(getClassName(clazz))
                 .append(" {\n");
         for (Method m : clazz.getMethods()) {
             if (!Modifier.isStatic(m.getModifiers()) && !Modifier.isFinal(m.getModifiers())) {
-                sourceCode.append("\tpublic ").append(m.getReturnType().getName().replace(DOLLAR, DOT)).append(" ")
+                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("> ");
+                }
+                sourceCode.append(getClassName(m.getGenericReturnType())).append(" ")
                         .append(m.getName()).append("(");
-                Class<?>[] parameters = m.getParameterTypes();
+                Type[] parameters = m.getGenericParameterTypes();
                 for (int i = 0; i < parameters.length; i++) {
                     sourceCode.append(getParameterName(parameters[i])).append(" p").append(i);
                     if (i < parameters.length - 1) {
@@ -34,8 +54,9 @@ public class ConstructionUtil {
                 }
                 sourceCode.append(") {\n");
                 if (!m.getReturnType().equals(void.class)) {
-                    sourceCode.append("\t\treturn ").append(OmniConstructor.class.getName().replace(DOLLAR, DOT)).append(".")
-                            .append("newInstance(").append(m.getReturnType().getName().replace(DOLLAR, DOT)).append(".class);\n");
+                    sourceCode.append("\t\treturn (").append(getClassName(m.getGenericReturnType())).append(") ")
+                            .append(getClassName(OmniConstructor.class)).append(".")
+                            .append("newInstance(").append(getClassName(m.getReturnType())).append(".class);\n");
                 }
                 sourceCode.append("\t}\n");
             }
@@ -45,6 +66,8 @@ public class ConstructionUtil {
         try {
             return (T) InMemoryJavaCompiler.newInstance()
                     .useParentClassLoader(clazz.getClassLoader())
+                    .useOptions("-Xlint:unchecked")
+                    .ignoreWarnings()
                     .compile(clazz.getPackage().getName() + DOT + getSubclassName(clazz), sourceCode.toString())
                     .newInstance();
         } catch (Exception e) {
@@ -52,11 +75,20 @@ public class ConstructionUtil {
         }
     }
 
-    private static String getParameterName(Class<?> parameter) {
-        if (parameter.isArray()) {
-            return getParameterName(parameter.getComponentType()) + "[]";
+    private static String getClassName(Type clazz) {
+        if (clazz instanceof Class) {
+            return ((Class<?>)clazz).getName().replace(DOLLAR, DOT);
+        } else if (clazz instanceof TypeVariable) {
+            return ((TypeVariable<?>)clazz).getName();
         }
-        return parameter.getName().replace(DOLLAR, DOT);
+        return clazz.toString().replaceAll("@.*$", "").replaceAll("^.* ", "");
+    }
+
+    private static String getParameterName(Type parameter) {
+        if (parameter instanceof Class && ((Class<?>)parameter).isArray()) {
+            return getParameterName(((Class<?>)parameter).getComponentType()) + "[]";
+        }
+        return getClassName(parameter);
     }
 
     private static String getSubclassName(Class<?> clazz) {
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 862117a..e84a52f 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
@@ -13,6 +13,7 @@ class ConstructionUtilTest {
         int func2(double d, boolean b);
         String fun3(String s, byte[] b);
         EmptyInterface fun4(RealInterface i);
+        <T> T fun5(T i);
     }
 
     public static abstract class AbstractClazz implements RealInterface {