diff --git "a/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/AbstractAnimal.java" "b/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/AbstractAnimal.java"
new file mode 100644
index 0000000..56cb20f
--- /dev/null
+++ "b/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/AbstractAnimal.java"
@@ -0,0 +1,8 @@
+package poly.ex4;
+
+public abstract class AbstractAnimal {
+
+    // 순수 추상 클래스
+    public abstract void sound();
+    public abstract void move();
+}
diff --git "a/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/AbstractMain.java" "b/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/AbstractMain.java"
new file mode 100644
index 0000000..fbab6cd
--- /dev/null
+++ "b/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/AbstractMain.java"
@@ -0,0 +1,33 @@
+package poly.ex4;
+public class AbstractMain {
+    public static void main(String[] args) {
+//        추상클래스 생성 불가
+//        AbstractAnimal animal = new AbstractAnimal();
+
+        Dog dog = new Dog();
+        Cat cat = new Cat();
+        Caw caw = new Caw();
+
+        soundAnimal(dog);
+        soundAnimal(cat);
+        soundAnimal(caw);
+
+        moveAnimal(dog);
+        moveAnimal(cat);
+        moveAnimal(caw);
+    }
+
+    // 변하지 않는 부분
+    private static void soundAnimal(AbstractAnimal animal) {
+        System.out.println("동물 소리 테스트 시작");
+        animal.sound();
+        System.out.println("동물 소리 테스트 종료");
+    }
+
+    // 변하지 않는 부분
+    private static void moveAnimal(AbstractAnimal animal) {
+        System.out.println("동물 이동 테스트 시작");
+        animal.move();
+        System.out.println("동물 이동 테스트 종료");
+    }
+}
diff --git "a/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/Cat.java" "b/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/Cat.java"
new file mode 100644
index 0000000..f7a5ca1
--- /dev/null
+++ "b/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/Cat.java"
@@ -0,0 +1,13 @@
+package poly.ex4;
+
+public class Cat extends AbstractAnimal {
+    @Override
+    public void sound() {
+        System.out.println("냐옹");
+    }
+
+    @Override
+    public void move() {
+        System.out.println("고양이 이동");
+    }
+}
diff --git "a/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/Caw.java" "b/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/Caw.java"
new file mode 100644
index 0000000..f8b441b
--- /dev/null
+++ "b/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/Caw.java"
@@ -0,0 +1,13 @@
+package poly.ex4;
+
+public class Caw extends AbstractAnimal {
+    @Override
+    public void sound() {
+        System.out.println("음메");
+    }
+
+    @Override
+    public void move() {
+        System.out.println("소 이동");
+    }
+}
diff --git "a/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/Dog.java" "b/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/Dog.java"
new file mode 100644
index 0000000..4125495
--- /dev/null
+++ "b/\352\271\200\354\225\204\353\246\260/java-basic/src/poly/ex4/Dog.java"
@@ -0,0 +1,13 @@
+package poly.ex4;
+
+public class Dog extends AbstractAnimal {
+    @Override
+    public void sound() {
+        System.out.println("멍멍");
+    }
+
+    @Override
+    public void move() {
+        System.out.println("개 이동");
+    }
+}