diff --git a/app/api/study_cards.py b/app/api/study_cards.py
index c5047ba..5c4914e 100644
--- a/app/api/study_cards.py
+++ b/app/api/study_cards.py
@@ -38,6 +38,7 @@ class CardEvidence(BaseModel):
 
 class CardItem(BaseModel):
     id: int
+    source_kind: str = "question"
     format: str
     cue: str
     fact: str
@@ -142,19 +143,34 @@ async def list_cards(
         ).all()
         q_meta = {r.id: (r.question_text, r.correct_choice) for r in q_rows}
 
-    # 그룹핑 (출제순서=rows 순서 유지)
-    groups: dict[int | None, CardQuestionGroup] = {}
-    order: list[int | None] = []
+    # 그룹핑 (출제순서=rows 순서 유지). question 카드는 출처 문제별,
+    # manual(직접 추가) 카드는 extra.material 별로 묶는다.
+    groups: dict[str, CardQuestionGroup] = {}
+    order: list[str] = []
     for c in rows:
-        key = c.source_question_id
-        if key not in groups:
-            qt, cc = q_meta.get(key, (None, None)) if key is not None else (None, None)
-            groups[key] = CardQuestionGroup(source_question_id=key, question_text=qt, correct_choice=cc, cards=[])
-            order.append(key)
-        groups[key].cards.append(
+        if c.source_question_id is not None:
+            gkey = f"q:{c.source_question_id}"
+        else:
+            material = c.extra.get("material") if isinstance(c.extra, dict) else None
+            gkey = f"m:{material or '직접 추가'}"
+        if gkey not in groups:
+            if c.source_question_id is not None:
+                qt, cc = q_meta.get(c.source_question_id, (None, None))
+                groups[gkey] = CardQuestionGroup(
+                    source_question_id=c.source_question_id, question_text=qt, correct_choice=cc, cards=[]
+                )
+            else:
+                material = c.extra.get("material") if isinstance(c.extra, dict) else None
+                groups[gkey] = CardQuestionGroup(
+                    source_question_id=None,
+                    question_text=(f"[자료] {material}" if material else "직접 추가 카드"),
+                    correct_choice=None, cards=[],
+                )
+            order.append(gkey)
+        groups[gkey].cards.append(
             CardItem(
-                id=c.id, format=c.format, cue=c.cue, fact=c.fact, cloze_text=c.cloze_text,
-                needs_review=c.needs_review, flagged_by=c.flagged_by,
+                id=c.id, source_kind=c.source_kind, format=c.format, cue=c.cue, fact=c.fact,
+                cloze_text=c.cloze_text, needs_review=c.needs_review, flagged_by=c.flagged_by,
                 evidence=ev_by_card.get(c.id, []),
             )
         )
@@ -221,8 +237,8 @@ async def update_card(
         raise HTTPException(status_code=409, detail="같은 정답의 중복 카드가 이미 있습니다")
 
     return CardItem(
-        id=card.id, format=card.format, cue=card.cue, fact=card.fact, cloze_text=card.cloze_text,
-        needs_review=card.needs_review, flagged_by=card.flagged_by, evidence=[],
+        id=card.id, source_kind=card.source_kind, format=card.format, cue=card.cue, fact=card.fact,
+        cloze_text=card.cloze_text, needs_review=card.needs_review, flagged_by=card.flagged_by, evidence=[],
     )
 
 
diff --git a/frontend/src/routes/study/cards-review/+page.svelte b/frontend/src/routes/study/cards-review/+page.svelte
index 240fd02..ed828ba 100644
--- a/frontend/src/routes/study/cards-review/+page.svelte
+++ b/frontend/src/routes/study/cards-review/+page.svelte
@@ -211,6 +211,8 @@
                   </div>
                   {#if c.evidence?.length}
                     <div class="mt-2 text-[11px] text-dim">근거: {c.evidence[0].snippet}</div>
+                  {:else if c.source_kind === 'manual'}
+                    <div class="mt-2 text-[11px] text-faint">출처: 직접 추가 자료</div>
                   {:else}
                     <div class="mt-2 text-[11px] text-faint">근거: 확정 풀이(비정량 개념)</div>
                   {/if}