diff --git a/web/app/routes/$userName+/page+/$slug+/edit/functions/mutations.server.ts b/web/app/routes/$userName+/page+/$slug+/edit/functions/mutations.server.ts
index 7736c1ad..1dd817c6 100644
--- a/web/app/routes/$userName+/page+/$slug+/edit/functions/mutations.server.ts
+++ b/web/app/routes/$userName+/page+/$slug+/edit/functions/mutations.server.ts
@@ -1,5 +1,4 @@
 import { prisma } from "~/utils/prisma";
-import { generateHashForText } from "../utils/generateHashForText";
 
 export async function upsertPageWithHtml(
 	pageSlug: string,
@@ -24,26 +23,10 @@ export async function upsertPageWithHtml(
 export async function upsertTitle(pageSlug: string, title: string) {
 	const page = await prisma.page.findUnique({ where: { slug: pageSlug } });
 	if (!page) return;
-	const titleHash = generateHashForText(title, 0);
 	await prisma.page.update({
 		where: { id: page.id },
 		data: { title: title },
 	});
-	return await prisma.sourceText.upsert({
-		where: {
-			pageId_textAndOccurrenceHash: {
-				pageId: page.id,
-				textAndOccurrenceHash: titleHash,
-			},
-		},
-		update: { text: title },
-		create: {
-			pageId: page.id,
-			textAndOccurrenceHash: titleHash,
-			text: title,
-			number: 0,
-		},
-	});
 }
 
 export async function upsertTags(tags: string[], pageId: number) {
diff --git a/web/app/routes/$userName+/page+/$slug+/edit/utils/processHtmlContent.test.ts b/web/app/routes/$userName+/page+/$slug+/edit/utils/processHtmlContent.test.ts
index 8ddf8866..1056e5b1 100644
--- a/web/app/routes/$userName+/page+/$slug+/edit/utils/processHtmlContent.test.ts
+++ b/web/app/routes/$userName+/page+/$slug+/edit/utils/processHtmlContent.test.ts
@@ -239,4 +239,68 @@ describe("processHtmlContent", () => {
 		// 各タイトル occurrence が異なる ID を持つことを確認
 		expect(titleOccurrences[0].id).not.toBe(titleOccurrences[1].id);
 	});
+
+	test("同一HTMLを再度処理した場合に、編集していない箇所のsource_textsが維持されるか確認", async () => {
+		const pageSlug = "html-no-edit-test-page";
+		const title = "No Edit Title";
+		const htmlInput = `
+			<p>Line A</p>
+			<p>Line B</p>
+			<p>Line C</p>
+		`;
+	
+		const user = await prisma.user.upsert({
+			where: { id: 13 },
+			create: {
+				id: 13,
+				userName: "noedit",
+				email: "noedit@example.com",
+				displayName: "noedit",
+				icon: "noedit",
+			},
+			update: {},
+		});
+	
+		// 初回処理
+		await processHtmlContent(title, htmlInput, pageSlug, user.id, "en", true);
+	
+		const dbPage1 = await prisma.page.findUnique({
+			where: { slug: pageSlug },
+			include: { sourceTexts: true },
+		});
+		expect(dbPage1).not.toBeNull();
+		if (!dbPage1) return;
+	
+		// 初回処理時のIDを記憶
+		const originalTextIdMap = new Map<string, number>();
+		for (const st of dbPage1.sourceTexts) {
+			originalTextIdMap.set(st.text, st.id);
+		}
+		expect(originalTextIdMap.size).toBeGreaterThanOrEqual(3);
+	
+		// 変更なしで再度同一HTMLを処理
+		await processHtmlContent(title, htmlInput, pageSlug, user.id, "en", true);
+	
+		const dbPage2 = await prisma.page.findUnique({
+			where: { slug: pageSlug },
+			include: { sourceTexts: true },
+		});
+		expect(dbPage2).not.toBeNull();
+		if (!dbPage2) return;
+	
+		// 再処理後のIDマッピングを取得
+		const afterTextIdMap = new Map<string, number>();
+		for (const st of dbPage2.sourceTexts) {
+			afterTextIdMap.set(st.text, st.id);
+		}
+	
+		// 全てのテキストでIDが変わっていないことを確認
+		for (const [text, originalId] of originalTextIdMap.entries()) {
+			console.log(text, originalId);
+			expect(afterTextIdMap.get(text)).toBe(originalId);
+		}
+	
+		// source_textsの数が増減していないこと（無駄な消去がないこと）
+		expect(dbPage2.sourceTexts.length).toBe(dbPage1.sourceTexts.length);
+	});
 });
diff --git a/web/app/routes/$userName+/page+/$slug+/edit/utils/processHtmlContent.ts b/web/app/routes/$userName+/page+/$slug+/edit/utils/processHtmlContent.ts
index bcc21f37..6e0950a7 100644
--- a/web/app/routes/$userName+/page+/$slug+/edit/utils/processHtmlContent.ts
+++ b/web/app/routes/$userName+/page+/$slug+/edit/utils/processHtmlContent.ts
@@ -42,7 +42,7 @@ function extractTextFromHAST(node: Parent): string {
 	});
 	return result;
 }
-export function rehypeAddDataId(pageId: number): Plugin<[], Root> {
+export function rehypeAddDataId(pageId: number, title: string): Plugin<[], Root> {
 	return function attacher() {
 		return async (tree: Root, file: VFile) => {
 			const textOccurrenceMap = new Map<string, number>();
@@ -74,11 +74,18 @@ export function rehypeAddDataId(pageId: number): Plugin<[], Root> {
 				}
 			});
 
+
 			const allTextsForDb = blocks.map((block, index) => ({
 				text: block.text,
 				textAndOccurrenceHash: block.textAndOccurrenceHash,
 				number: index + 1,
-			}));
+			}))
+	
+			allTextsForDb.push({
+				text: title,
+				textAndOccurrenceHash: generateHashForText(title, 0),
+				number: 0,
+			});
 
 			const hashToId = await synchronizePageSourceTexts(pageId, allTextsForDb);
 
@@ -127,7 +134,7 @@ export async function processHtmlContent(
 		.use(rehypeRemark) // HAST→MDAST
 		.use(remarkGfm) // GFM拡張
 		.use(remarkRehype, { allowDangerousHtml: true }) // MDAST→HAST
-		.use(rehypeAddDataId(page.id))
+		.use(rehypeAddDataId(page.id, title))
 		.use(rehypeRaw) // 生HTMLを処理
 		.use(rehypeStringify, { allowDangerousHtml: true }) // HAST→HTML
 		.process(htmlInput);
diff --git a/web/scripts/processMarkdownContent.ts b/web/scripts/processMarkdownContent.ts
index 831847b3..c6ae97ad 100644
--- a/web/scripts/processMarkdownContent.ts
+++ b/web/scripts/processMarkdownContent.ts
@@ -28,7 +28,7 @@ export async function processMarkdownContent(
 	const file = await remark()
 		.use(remarkGfm)
 		.use(remarkRehype)
-		.use(rehypeAddDataId(page.id))
+		.use(rehypeAddDataId(page.id, title))
 		.use(rehypeRaw)
 		.use(rehypeStringify, { allowDangerousHtml: true })
 		.process(body);