diff --git a/src/main/java/com/prgrms/prolog/domain/post/service/PostServiceImpl.java b/src/main/java/com/prgrms/prolog/domain/post/service/PostServiceImpl.java
index 9e0f88b..26ddf9a 100644
--- a/src/main/java/com/prgrms/prolog/domain/post/service/PostServiceImpl.java
+++ b/src/main/java/com/prgrms/prolog/domain/post/service/PostServiceImpl.java
@@ -94,8 +94,8 @@ public Page<PostResponse> findAll(Pageable pageable) {
 	@Override
 	@Transactional
 	public PostResponse update(UpdateRequest update, Long userId, Long postId) {
-		Post findPost = postRepository.joinUserFindById(postId)
-			.orElseThrow(() -> new IllegalArgumentException("exception.post.notExists"));
+		Post findPost = postRepository.findById(postId)
+			.orElseThrow(() -> new IllegalArgumentException(POST_NOT_EXIST_MESSAGE));
 
 		if (!findPost.getUser().checkSameUserId(userId)) {
 			throw new IllegalArgumentException("exception.post.not.owner");
@@ -114,6 +114,12 @@ public PostResponse update(UpdateRequest update, Long userId, Long postId) {
 	public void delete(Long postId) {
 		Post findPost = postRepository.findById(postId)
 			.orElseThrow(() -> new IllegalArgumentException(POST_NOT_EXIST_MESSAGE));
+		Set<RootTag> findRootTags = postTagRepository.joinRootTagFindByPostId(findPost.getId())
+			.stream()
+			.map(PostTag::getRootTag)
+			.collect(Collectors.toSet());
+		removeOrDecreaseUserTags(findPost.getUser(), findRootTags);
+		postTagRepository.deleteByPostId(postId);
 		postRepository.delete(findPost);
 	}
 
diff --git a/src/main/java/com/prgrms/prolog/domain/posttag/repository/PostTagRepository.java b/src/main/java/com/prgrms/prolog/domain/posttag/repository/PostTagRepository.java
index c42fd74..2b79d56 100644
--- a/src/main/java/com/prgrms/prolog/domain/posttag/repository/PostTagRepository.java
+++ b/src/main/java/com/prgrms/prolog/domain/posttag/repository/PostTagRepository.java
@@ -30,4 +30,12 @@ void deleteByPostIdAndRootTagIds(
 		WHERE pt.post.id = :postId
 		""")
 	Set<PostTag> joinRootTagFindByPostId(@Param(value = "postId") Long postId);
+
+	@Modifying
+	@Query("""
+		DELETE
+		FROM PostTag pt
+		WHERE pt.post.id = :postId
+		""")
+	void deleteByPostId(@Param(value = "postId") Long postId);
 }
diff --git a/src/main/java/com/prgrms/prolog/domain/series/api/SeriesController.java b/src/main/java/com/prgrms/prolog/domain/series/api/SeriesController.java
index 395ceaa..de6c972 100644
--- a/src/main/java/com/prgrms/prolog/domain/series/api/SeriesController.java
+++ b/src/main/java/com/prgrms/prolog/domain/series/api/SeriesController.java
@@ -3,8 +3,8 @@
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 import com.prgrms.prolog.domain.series.dto.SeriesResponse;
@@ -20,9 +20,9 @@ public class SeriesController {
 
 	private final SeriesService seriesService;
 
-	@GetMapping("/{title}")
+	@GetMapping()
 	ResponseEntity<SeriesResponse> findSeriesByTitle(
-		@PathVariable String title,
+		@RequestParam String title,
 		@AuthenticationPrincipal JwtAuthentication user
 	) {
 		return ResponseEntity.ok(
diff --git a/src/test/java/com/prgrms/prolog/domain/series/api/SeriesControllerTest.java b/src/test/java/com/prgrms/prolog/domain/series/api/SeriesControllerTest.java
index ca14c6c..4a646bd 100644
--- a/src/test/java/com/prgrms/prolog/domain/series/api/SeriesControllerTest.java
+++ b/src/test/java/com/prgrms/prolog/domain/series/api/SeriesControllerTest.java
@@ -87,8 +87,9 @@ void findSeriesByTitleTest() throws Exception {
 		// given
 		Claims claims = Claims.from(savedUser.getId(), USER_ROLE);
 		// when
-		mockMvc.perform(get("/api/v1/series/{title}", SERIES_TITLE)
+		mockMvc.perform(get("/api/v1/series")
 				.header(AUTHORIZATION, BEARER_TYPE + jwtTokenProvider.createAccessToken(claims))
+				.param("title", SERIES_TITLE)
 			)
 			// then
 			.andExpectAll(