diff --git a/src/components/game-distribution/GameDistributionPages.test.tsx b/src/components/game-distribution/GameDistributionPages.test.tsx
index 094492635..e9a9552a2 100644
--- a/src/components/game-distribution/GameDistributionPages.test.tsx
+++ b/src/components/game-distribution/GameDistributionPages.test.tsx
@@ -1911,6 +1911,36 @@ describe('GameThemePage', () => {
     expect(await screen.findByText('主题不存在')).toBeTruthy();
     expect(screen.getByRole('button', { name: '重试' })).toBeTruthy();
   });
+
+  it('roots 被截断时给出明确提示，且总数用 memberCount 而不是 roots 长度', async () => {
+    getThemeMock.mockResolvedValue({
+      themeId: 'theme-3',
+      name: '大主题',
+      summary: '',
+      badge: '',
+      memberCount: 120,
+      rootsTruncated: true,
+      roots: [rootGame('game-root-1', '根一')],
+    });
+    getGameLineageMock.mockResolvedValue({
+      rootGameId: 'game-root-1',
+      root: null,
+      nodes: [],
+      truncated: false,
+    });
+    render(
+      <GameThemePage
+        themeId="theme-3"
+        onBack={vi.fn()}
+        onOpenDetail={vi.fn()}
+      />,
+    );
+
+    // 总数是真实可见成员数（120），不是这一页拿到的 1 个。
+    expect(await screen.findByText('共 120 棵作品树')).toBeTruthy();
+    expect(screen.getByText(/这里只显示前 1 个，共 120 个/u)).toBeTruthy();
+    expect(screen.queryByText('共 1 棵作品树')).toBeNull();
+  });
 });
 
 describe('GameDetailPage 共创主题入口', () => {
diff --git a/src/components/game-distribution/GameThemePage.tsx b/src/components/game-distribution/GameThemePage.tsx
index 7928b50cd..0bd54af67 100644
--- a/src/components/game-distribution/GameThemePage.tsx
+++ b/src/components/game-distribution/GameThemePage.tsx
@@ -158,6 +158,22 @@ export function GameThemePage({
         </div>
       ) : null}
 
+      {theme ? (
+        <p className="game-theme-summary__meta">
+          共 {theme.memberCount} 棵作品树
+        </p>
+      ) : null}
+      {theme?.rootsTruncated ? (
+        /*
+          总数一律用 `memberCount`（真实可见成员数，不截断）；`roots.length` 只是这一页拿到几个。
+          两者不再保证相等，所以这里显式区分「显示前 N 个」与「共 M 个」。
+        */
+        <p className="game-lineage-notice" role="status">
+          这个主题的根较多：这里只显示前 {theme.roots.length} 个，共{' '}
+          {theme.memberCount} 个。
+        </p>
+      ) : null}
+
       {isLoading && !theme ? (
         <div className="game-loading-panel">正在加载共创主题…</div>
       ) : null}
diff --git a/src/components/game-distribution/gameDistribution.css b/src/components/game-distribution/gameDistribution.css
index 9c2d0d939..85ad651db 100644
--- a/src/components/game-distribution/gameDistribution.css
+++ b/src/components/game-distribution/gameDistribution.css
@@ -636,6 +636,12 @@
   line-height: 1.6;
   overflow-wrap: anywhere;
 }
+.game-theme-summary__meta {
+  margin: 0;
+  color: var(--platform-text-soft);
+  font-size: 0.8rem;
+  overflow-wrap: anywhere;
+}
 .game-theme-trees {
   display: flex;
   flex-direction: column;
diff --git a/src/services/gameDistributionClient.ts b/src/services/gameDistributionClient.ts
index c0dbcc563..7d5f6dae3 100644
--- a/src/services/gameDistributionClient.ts
+++ b/src/services/gameDistributionClient.ts
@@ -400,6 +400,13 @@ export type GameDistributionThemeSummary = {
 /** 主题详情：摘要 + 成员根清单（逐条是公开目录同一份投影）。 */
 export type GameDistributionThemeDetail = GameDistributionThemeSummary & {
   roots: GameDistributionGame[];
+  /**
+   * `roots` 是否被服务端的响应体积上限截断（与族谱响应的 `truncated` 同一种约定）。
+   *
+   * **`memberCount` 与 `roots.length` 不再保证相等**：`memberCount` 是真实可见成员数（不截断），
+   * `roots` 可能只含前 50 个。展示总数一律用 `memberCount`，这个布尔只负责决定要不要提示。
+   */
+  rootsTruncated: boolean;
 };
 
 function normalizeThemeList(value: unknown): GameDistributionThemeSummary[] {
@@ -464,6 +471,8 @@ export async function getTheme(
     summary?: string;
     badge?: string;
     memberCount?: number;
+    /** `roots` 被响应体积上限截断：与 `roots` 同层，空成员时也是 `false`（不是缺键）。 */
+    rootsTruncated?: boolean;
     roots?: unknown;
   }>(
     `/themes/${encodeURIComponent(normalizedThemeId)}`,
@@ -477,6 +486,7 @@ export async function getTheme(
     summary: payload.summary ?? '',
     badge: payload.badge ?? '',
     memberCount: payload.memberCount ?? 0,
+    rootsTruncated: payload.rootsTruncated === true,
     roots: normalizeGameList(payload.roots),
   };
 }