diff --git a/src/services/count-same-renotes.ts b/src/services/count-same-renotes.ts
new file mode 100644
index 000000000..a20b4fbf8
--- /dev/null
+++ b/src/services/count-same-renotes.ts
@@ -0,0 +1,15 @@
+import { Notes } from '../models';
+
+export default async function(userId: string, renoteId: string, excludeNoteId: string | undefined): Promise<number> {
+	// 指定したユーザーの指定したノートのリノートがいくつあるか数える
+	const query = Notes.createQueryBuilder('note')
+		.where('note.userId = :userId', { userId })
+		.andWhere('note.renoteId = :renoteId', { renoteId })
+
+	// 指定した投稿を除く
+	if (excludeNoteId) {
+		query.andWhere('note.id != :excludeNoteId', { excludeNoteId })
+	}
+
+	return await query.getCount();
+}
diff --git a/src/services/note/create.ts b/src/services/note/create.ts
index 3426083e3..98b173180 100644
--- a/src/services/note/create.ts
+++ b/src/services/note/create.ts
@@ -30,6 +30,7 @@ import { isDuplicateKeyValueError } from '../../misc/is-duplicate-key-value-erro
 import { ensure } from '../../prelude/ensure';
 import { checkHitAntenna } from '../../misc/check-hit-antenna';
 import { addNoteToAntenna } from '../add-note-to-antenna';
+import countSameRenotes from '../count-same-renotes';
 
 type NotificationType = 'reply' | 'renote' | 'quote' | 'mention';
 
@@ -236,7 +237,8 @@ export default async (user: User, data: Option, silent = false) => new Promise<N
 		saveReply(data.reply, note);
 	}
 
-	if (data.renote) {
+	//この投稿を除く指定したユーザーによる指定したノートのリノートが存在しないとき
+	if (data.renote && (await countSameRenotes(user.id, data.renote.id, note.id) === 0)) {
 		incRenoteCount(data.renote);
 	}
 
diff --git a/src/services/note/delete.ts b/src/services/note/delete.ts
index 29b9c576d..6561120b4 100644
--- a/src/services/note/delete.ts
+++ b/src/services/note/delete.ts
@@ -11,6 +11,7 @@ import { Note } from '../../models/entities/note';
 import { Notes, Users, Instances } from '../../models';
 import { notesChart, perUserNotesChart, instanceChart } from '../chart';
 import { deliverToFollowers } from '../../remote/activitypub/deliver-manager';
+import countSameRenotes from '../count-same-renotes';
 
 /**
  * 投稿を削除します。
@@ -20,7 +21,8 @@ import { deliverToFollowers } from '../../remote/activitypub/deliver-manager';
 export default async function(user: User, note: Note, quiet = false) {
 	const deletedAt = new Date();
 
-	if (note.renoteId) {
+	//この投稿を除く指定したユーザーによる指定したノートのリノートが存在しないとき
+	if (note.renoteId && (await countSameRenotes(user.id, note.renoteId, note.id)) === 0) {
 		Notes.decrement({ id: note.renoteId }, 'renoteCount', 1);
 		Notes.decrement({ id: note.renoteId }, 'score', 1);
 	}