diff --git a/src/main/java/com/newfit/reservation/domains/reservation/dto/request/ReservationRequest.java b/src/main/java/com/newfit/reservation/domains/reservation/dto/request/ReservationRequest.java
index 548b5b79..6257d56f 100644
--- a/src/main/java/com/newfit/reservation/domains/reservation/dto/request/ReservationRequest.java
+++ b/src/main/java/com/newfit/reservation/domains/reservation/dto/request/ReservationRequest.java
@@ -15,7 +15,6 @@
 @NoArgsConstructor(access = AccessLevel.PROTECTED)
 public class ReservationRequest {
 
-	@Future
 	private LocalDateTime startAt;
 
 	@Future
diff --git a/src/main/java/com/newfit/reservation/domains/reservation/dto/request/ReservationUpdateRequest.java b/src/main/java/com/newfit/reservation/domains/reservation/dto/request/ReservationUpdateRequest.java
index dd8bd8a4..6da5b18a 100644
--- a/src/main/java/com/newfit/reservation/domains/reservation/dto/request/ReservationUpdateRequest.java
+++ b/src/main/java/com/newfit/reservation/domains/reservation/dto/request/ReservationUpdateRequest.java
@@ -17,8 +17,9 @@
 public class ReservationUpdateRequest {
 	@Min(1)
 	private Long equipmentGymId;
-	@Future
+
 	private LocalDateTime startAt;
+	
 	@Future
 	private LocalDateTime endAt;
 }
diff --git a/src/main/java/com/newfit/reservation/domains/reservation/repository/ReservationRepository.java b/src/main/java/com/newfit/reservation/domains/reservation/repository/ReservationRepository.java
index 3d91d4d5..f03d5ba3 100644
--- a/src/main/java/com/newfit/reservation/domains/reservation/repository/ReservationRepository.java
+++ b/src/main/java/com/newfit/reservation/domains/reservation/repository/ReservationRepository.java
@@ -39,4 +39,17 @@ List<Reservation> findAllByAuthorityIdAndStartAtAndEndAt(@Param("authorityId") L
 	List<Reservation> findAllByEquipmentGymIdIdAndStartAtAndEndAt(@Param("equipmentGymId") Long equipmentGymId,
 		@Param("startAt") LocalDateTime startAt,
 		@Param("endAt") LocalDateTime endAt);
+
+	@Query(value = "select r.* from Reservation r " +
+		"join authority a " +
+		"on a.id=:authorityId " +
+		"where ( " +
+		"(:startAt BETWEEN r.start_at AND r.end_at) " +
+		"OR (:endAt BETWEEN r.start_at AND r.end_at) " +
+		"OR (:startAt <= r.start_at AND r.end_at <= :endAt)) " +
+		"AND (r.id <> :reservationId);", nativeQuery = true)
+	List<Reservation> findAllByAuthorityIdAndStartAtAndEndAtExcludingCurrent(@Param("authorityId") Long authorityId,
+		@Param("startAt") LocalDateTime startAt,
+		@Param("endAt") LocalDateTime endAt,
+		@Param("reservationId") Long reservationId);
 }
diff --git a/src/main/java/com/newfit/reservation/domains/reservation/service/ReservationService.java b/src/main/java/com/newfit/reservation/domains/reservation/service/ReservationService.java
index 118d414f..e8ac0afb 100644
--- a/src/main/java/com/newfit/reservation/domains/reservation/service/ReservationService.java
+++ b/src/main/java/com/newfit/reservation/domains/reservation/service/ReservationService.java
@@ -49,6 +49,7 @@ public void reserve(Long authorityId,
 		LocalDateTime endAt = request.getEndAt();
 
 		validateTime(startAt, endAt, authority);
+		validateMyReservationOverlap(authority, startAt, endAt);
 
 		EquipmentGym equipmentGym = equipmentGymRepository.findAvailableByEquipmentGymIdAndStartAtAndEndAt(
 				equipmentGymId, startAt, endAt)
@@ -58,12 +59,6 @@ public void reserve(Long authorityId,
 		reservationRepository.save(reservation);
 	}
 
-	private void validateLastTagAt(Authority authority) {
-		LocalDateTime tagAt = authority.getTagAt();
-		if (tagAt.isBefore(now().minusHours(2)))
-			throw new CustomException(EXPIRED_TAG);
-	}
-
 	@Transactional(readOnly = true)
 	public ReservationListResponse listReservation(Long equipmentGymId) {
 		EquipmentGym equipmentGym = equipmentGymRepository.findById(equipmentGymId)
@@ -87,6 +82,7 @@ public void update(Long reservationId, ReservationUpdateRequest request) {
 		LocalDateTime endAt = request.getEndAt();
 
 		validateTime(startAt, endAt, authority);
+		validateMyReservationOverlapExcludingCurrent(authority, startAt, endAt, reservationId);
 
 		if (equipmentGymId == null) {
 			targetReservation.updateTime(startAt, endAt);
@@ -114,13 +110,24 @@ private void validateUpdateTime(Long equipmentGymId, LocalDateTime startAt, Loca
 	}
 
 	private void validateTime(LocalDateTime startAt, LocalDateTime endAt, Authority authority) {
+		validateStartAtLowerBound(startAt);
 		validateLastTagAt(authority);
 		validateReservationIn2Hours(startAt, endAt);
 
 		Gym gym = authority.getGym();
 		gym.checkBusinessHour(startAt, endAt);
+	}
 
-		validateMyReservationOverlap(authority, startAt, endAt);
+	private void validateStartAtLowerBound(LocalDateTime startAt) {
+		if (startAt.isBefore(now().minusMinutes(1))) {
+			throw new CustomException(INVALID_RESERVATION_REQUEST);
+		}
+	}
+
+	private void validateLastTagAt(Authority authority) {
+		LocalDateTime tagAt = authority.getTagAt();
+		if (tagAt.isBefore(now().minusHours(2)))
+			throw new CustomException(EXPIRED_TAG);
 	}
 
 	private void validateMyReservationOverlap(Authority authority, LocalDateTime startAt, LocalDateTime endAt) {
@@ -131,6 +138,17 @@ private void validateMyReservationOverlap(Authority authority, LocalDateTime sta
 		}
 	}
 
+	private void validateMyReservationOverlapExcludingCurrent(Authority authority, LocalDateTime startAt,
+		LocalDateTime endAt,
+		Long reservationId) {
+		List<Reservation> reservations = reservationRepository.findAllByAuthorityIdAndStartAtAndEndAtExcludingCurrent(
+			authority.getId(),
+			startAt, endAt, reservationId);
+		if (!reservations.isEmpty()) {
+			throw new CustomException(INVALID_RESERVATION_REQUEST);
+		}
+	}
+
 	public void delete(Long reservationId) {
 		reservationRepository.deleteById(reservationId);
 	}