diff --git a/tdd_practice/pickingTDD/src/main/java/com/example/pickingtdd/service/OrderService.java b/tdd_practice/pickingTDD/src/main/java/com/example/pickingtdd/service/OrderService.java
index 2792c0e0..3c50e22e 100644
--- a/tdd_practice/pickingTDD/src/main/java/com/example/pickingtdd/service/OrderService.java
+++ b/tdd_practice/pickingTDD/src/main/java/com/example/pickingtdd/service/OrderService.java
@@ -4,5 +4,5 @@ import com.example.pickingtdd.entity.Order;
 
 public interface OrderService {
 
-    Order createOrder(Order order);
+    Order createOrder(Order order) throws Exception;
 }
diff --git a/tdd_practice/pickingTDD/src/main/java/com/example/pickingtdd/service/OrderServiceImpl.java b/tdd_practice/pickingTDD/src/main/java/com/example/pickingtdd/service/OrderServiceImpl.java
index 4eacd9df..39c77553 100644
--- a/tdd_practice/pickingTDD/src/main/java/com/example/pickingtdd/service/OrderServiceImpl.java
+++ b/tdd_practice/pickingTDD/src/main/java/com/example/pickingtdd/service/OrderServiceImpl.java
@@ -7,7 +7,21 @@ import org.springframework.stereotype.Service;
 public class OrderServiceImpl implements OrderService {
 
     @Override
-    public Order createOrder(Order order) {
-        return order;
+    public Order createOrder(Order order) throws Exception {
+        if (orderValidation(order)) {
+            return order;
+        } else {
+            throw new Exception("order validation fail");
+        }
+    }
+
+    private boolean orderValidation(Order order) {
+        if (order.getOrderId() == null) {
+            return false;
+        }
+        if (order.getState() == null || order.getState().length() == 0) {
+            return false;
+        }
+        return true;
     }
 }
diff --git a/tdd_practice/pickingTDD/src/test/java/com/example/pickingtdd/service/OrderServiceTests.java b/tdd_practice/pickingTDD/src/test/java/com/example/pickingtdd/service/OrderServiceTests.java
index 62b289f1..00a12753 100644
--- a/tdd_practice/pickingTDD/src/test/java/com/example/pickingtdd/service/OrderServiceTests.java
+++ b/tdd_practice/pickingTDD/src/test/java/com/example/pickingtdd/service/OrderServiceTests.java
@@ -2,25 +2,65 @@ package com.example.pickingtdd.service;
 
 import com.example.pickingtdd.entity.Order;
 import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 
+import static org.junit.jupiter.api.Assertions.*;
+
 @SpringBootTest
 public class OrderServiceTests {
 
     @Autowired
     OrderService orderService;
 
+    Order orderSuccess;
+    Order orderFail;
+
+    @BeforeEach
+    void init() {
+        orderSuccess = new Order();
+        orderSuccess.setOrderId(1L);
+        orderSuccess.setState("Ordered");
+
+        orderFail = new Order();
+        orderFail.setOrderId(null);
+        orderFail.setState("");
+    }
+
     @Test
-    void create_order_success() {
+    void createOrder_success() {
         Order order = new Order();
-        order.setOrderId(1L);
-        order.setState("Ordered");
+        try {
+            order = orderService.createOrder(orderSuccess);
+        } catch (Exception e) {
+            // do nothing
+        }
 
-        order = orderService.createOrder(order);
+        assertEquals(1L, order.getOrderId());
+        assertEquals("Ordered", order.getState());
+    }
 
-        Assertions.assertEquals(1L, order.getOrderId());
-        Assertions.assertEquals("Ordered", order.getState());
+    @Test
+    void orderValidation_success() {
+        Order order = new Order();
+        try {
+            order = orderService.createOrder(orderSuccess);
+        } catch (Exception e) {
+            fail("should not throw exception");
+        }
+
+        assertEquals(1L, order.getOrderId());
+        assertEquals("Ordered", order.getState());
+    }
+
+    @Test
+    void orderValidation_fail() {
+        Exception e = assertThrows(Exception.class, () -> {
+            orderService.createOrder(orderFail);
+        });
+
+        assertEquals("order validation fail", e.getMessage());
     }
 }
diff --git a/tdd_practice/pickingTDD/todo.txt b/tdd_practice/pickingTDD/todo.txt
index 2c06da86..f2cf4343 100644
--- a/tdd_practice/pickingTDD/todo.txt
+++ b/tdd_practice/pickingTDD/todo.txt
@@ -8,6 +8,7 @@ SKU
 주문 -> 피킹리스트 -> 피커 -> 피킹완료
 
 ------- TO-DO -------
-[] ORDER 검증
+[] Order.state => enum 변경
 
+[v] ORDER 검증
 [v] ORDER 생성