diff --git a/src/test/java/roomescape/payment/business/PaymentServiceKTest.kt b/src/test/java/roomescape/payment/business/PaymentServiceKTest.kt
new file mode 100644
index 00000000..e72b228c
--- /dev/null
+++ b/src/test/java/roomescape/payment/business/PaymentServiceKTest.kt
@@ -0,0 +1,129 @@
+package roomescape.payment.business
+
+import io.kotest.assertions.assertSoftly
+import io.kotest.assertions.throwables.shouldThrow
+import io.kotest.core.spec.style.FunSpec
+import io.kotest.matchers.shouldBe
+import io.mockk.every
+import io.mockk.just
+import io.mockk.mockk
+import io.mockk.runs
+import org.springframework.http.HttpStatus
+import roomescape.common.exception.ErrorType
+import roomescape.common.exception.RoomescapeException
+import roomescape.payment.infrastructure.persistence.CanceledPaymentRepository
+import roomescape.payment.infrastructure.persistence.PaymentRepository
+import roomescape.payment.web.PaymentCancel
+import roomescape.util.PaymentFixture
+import java.time.OffsetDateTime
+
+class PaymentServiceKTest : FunSpec({
+    val paymentRepository: PaymentRepository = mockk()
+    val canceledPaymentRepository: CanceledPaymentRepository = mockk()
+
+    val paymentService = PaymentService(paymentRepository, canceledPaymentRepository)
+
+    context("cancelPaymentByAdmin") {
+        val reservationId = 1L
+        test("reservationId로 paymentKey를 찾을 수 없으면 예외를 던진다.") {
+            every { paymentRepository.findPaymentKeyByReservationId(reservationId) } returns null
+
+            val exception = shouldThrow<RoomescapeException> {
+                paymentService.cancelPaymentByAdmin(reservationId)
+            }
+
+            assertSoftly(exception) {
+                this.errorType shouldBe ErrorType.PAYMENT_NOT_FOUND
+                this.httpStatus shouldBe HttpStatus.NOT_FOUND
+            }
+        }
+
+        context("reservationId로 paymentKey를 찾고난 후") {
+            val paymentKey = "test-payment-key"
+
+            every {
+                paymentRepository.findPaymentKeyByReservationId(reservationId)
+            } returns paymentKey
+
+            test("해당 paymentKey로 paymentEntity를 찾을 수 없으면 예외를 던진다.") {
+                every {
+                    paymentRepository.findByPaymentKey(paymentKey)
+                } returns null
+
+                val exception = shouldThrow<RoomescapeException> {
+                    paymentService.cancelPaymentByAdmin(reservationId)
+                }
+
+                assertSoftly(exception) {
+                    this.errorType shouldBe ErrorType.PAYMENT_NOT_FOUND
+                    this.httpStatus shouldBe HttpStatus.NOT_FOUND
+                }
+            }
+
+            test("해당 paymentKey로 paymentEntity를 찾고, cancelPaymentEntity를 저장한다.") {
+                val paymentEntity = PaymentFixture.create(paymentKey = paymentKey)
+
+                every {
+                    paymentRepository.findByPaymentKey(paymentKey)
+                } returns paymentEntity.also {
+                    every {
+                        paymentRepository.delete(it)
+                    } just runs
+                }
+
+                every {
+                    canceledPaymentRepository.save(any())
+                } returns PaymentFixture.createCanceled(
+                        id = 1L,
+                        paymentKey = paymentKey,
+                        cancelAmount = paymentEntity.totalAmount,
+                )
+
+                val result: PaymentCancel.Request = paymentService.cancelPaymentByAdmin(reservationId)
+
+                assertSoftly(result) {
+                    this.paymentKey shouldBe paymentKey
+                    this.amount shouldBe paymentEntity.totalAmount
+                    this.cancelReason shouldBe "고객 요청"
+                }
+            }
+        }
+    }
+
+    context("updateCanceledTime") {
+        val paymentKey = "test-payment-key"
+        val canceledAt = OffsetDateTime.now()
+
+        test("paymentKey로 canceledPaymentEntity를 찾을 수 없으면 예외를 던진다.") {
+            every {
+                canceledPaymentRepository.findByPaymentKey(paymentKey)
+            } returns null
+
+            val exception = shouldThrow<RoomescapeException> {
+                paymentService.updateCanceledTime(paymentKey, canceledAt)
+            }
+
+            assertSoftly(exception) {
+                this.errorType shouldBe ErrorType.PAYMENT_NOT_FOUND
+                this.httpStatus shouldBe HttpStatus.NOT_FOUND
+            }
+        }
+
+        test("paymentKey로 canceledPaymentEntity를 찾고, canceledAt을 업데이트한다.") {
+            val canceledPaymentEntity = PaymentFixture.createCanceled(
+                    paymentKey = paymentKey,
+                    canceledAt = canceledAt.minusMinutes(1)
+            )
+
+            every {
+                canceledPaymentRepository.findByPaymentKey(paymentKey)
+            } returns canceledPaymentEntity
+
+            paymentService.updateCanceledTime(paymentKey, canceledAt)
+
+            assertSoftly(canceledPaymentEntity) {
+                this.canceledAt shouldBe canceledAt
+            }
+        }
+    }
+})