diff --git a/proj-acquirex/src/test/java/com/acquirex/approval/ApprovalServiceTest.java b/proj-acquirex/src/test/java/com/acquirex/approval/ApprovalServiceTest.java
new file mode 100644
index 0000000..a1ef3aa
--- /dev/null
+++ b/proj-acquirex/src/test/java/com/acquirex/approval/ApprovalServiceTest.java
@@ -0,0 +1,63 @@
+package com.acquirex.approval;
+
+import com.acquirex.approval.domain.ApprovalDomain;
+import com.acquirex.approval.domain.ApprovalDomain.Request;
+import com.acquirex.approval.domain.ApprovalDomain.Response;
+import com.acquirex.approval.domain.ApprovalDomain.Status;
+import com.acquirex.approval.service.ApprovalService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import java.math.BigDecimal;
+import static org.junit.jupiter.api.Assertions.*;
+
+class ApprovalServiceTest {
+    private ApprovalService service;
+
+    @BeforeEach
+    void setUp() { service = new ApprovalService(); }
+
+    @Test
+    @DisplayName("유효한 요청으로 매입 승인 성공")
+    void processApproval_ValidRequest_Success() {
+        Request req = new Request("TXN-001", "MERCHANT-001", new BigDecimal("50000"), "1234567890123456");
+        Response res = service.processApproval(req);
+        assertEquals(Status.APPROVED, res.getStatus());
+        assertNotNull(res.getApprovalId());
+        assertTrue(res.getApprovalId().startsWith("APR-"));
+    }
+
+    @Test
+    @DisplayName("유효하지 않은 금액으로 매입 승인 거절")
+    void processApproval_InvalidAmount_Rejected() {
+        Request req = new Request("TXN-002", "MERCHANT-001", new BigDecimal("-1000"), "1234567890123456");
+        assertEquals(Status.REJECTED, service.processApproval(req).getStatus());
+    }
+
+    @Test
+    @DisplayName("유효하지 않은 카드번호로 매입 승인 거절")
+    void processApproval_InvalidCardNumber_Rejected() {
+        Request req = new Request("TXN-003", "MERCHANT-001", new BigDecimal("50000"), "12345");
+        assertEquals(Status.REJECTED, service.processApproval(req).getStatus());
+    }
+
+    @Test
+    @DisplayName("null 요청으로 매입 승인 거절")
+    void processApproval_NullRequest_Rejected() {
+        assertEquals(Status.REJECTED, service.processApproval(null).getStatus());
+    }
+
+    @Test
+    @DisplayName("유효한 승인 ID로 취소 성공")
+    void cancelApproval_ValidApprovalId_Success() {
+        Response res = service.cancelApproval("APR-12345678");
+        assertEquals(Status.CANCELLED, res.getStatus());
+    }
+
+    @Test
+    @DisplayName("유효하지 않은 승인 ID로 취소 거절")
+    void cancelApproval_InvalidApprovalId_Rejected() {
+        assertEquals(Status.REJECTED, service.cancelApproval("").getStatus());
+        assertEquals(Status.REJECTED, service.cancelApproval(null).getStatus());
+    }
+}
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