diff --git a/index.html b/index.html
index 56c7a7c..7e54a19 100644
--- a/index.html
+++ b/index.html
@@ -168,6 +168,9 @@
                         </section>
                         <section>
                           <h3>2 · 복사할 항목</h3>
+                          <div class="cp-tools">
+                            <button id="cp-items-reset" class="btn-o small" type="button">변경 항목으로 선택</button>
+                          </div>
                           <div id="cp-items" class="cp-chips"></div>
                           <p id="cp-none" class="muted small" hidden>이 부재는 복사 항목이 없습니다. 기둥·받침은 예정입니다.</p>
                           <p class="muted small">복사하지 않는 값: 좌표 · IP · 받침 EL · 코핑 상면 EL · 기초 하단 EL · 지반고 · 기둥 높이 · 말뚝 선단 EL · 계단 구간</p>
diff --git a/src/core/copy-targets.ts b/src/core/copy-targets.ts
index 994aedf..7400dbb 100644
--- a/src/core/copy-targets.ts
+++ b/src/core/copy-targets.ts
@@ -1,4 +1,5 @@
-import type { CopyItem } from './copy';
+import { COPY_ITEMS, type CopyItem } from './copy';
+import { overrideKeys, type PierValues } from './changes';
 import type { MemberId } from './shape-options';
 
 /** One pier as a target of 속성 복사. */
@@ -43,3 +44,12 @@ export const MEMBER_COPY_ITEMS: Record<MemberId, CopyItem[]> = {
 export function copyItemsFor(member: MemberId): CopyItem[] {
   return MEMBER_COPY_ITEMS[member];
 }
+
+/**
+ * The copy items whose values the 기준 pier has changed from the imported default (되돌리기가 보이는 항목).
+ * They are ticked by default; the user can change the ticks afterwards.
+ */
+export function copyItemsWithOverrides(source: PierValues): CopyItem[] {
+  const changed = new Set<string>(overrideKeys(source));
+  return (Object.keys(COPY_ITEMS) as CopyItem[]).filter((item) => COPY_ITEMS[item].keys.some((k) => changed.has(k)));
+}
diff --git a/src/main.ts b/src/main.ts
index 32179f3..ec4dd41 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -8,8 +8,8 @@ import { NOT_IMPLEMENTED_RULES, validateInput, validatePier } from './core/valid
 import { buildTemplateWorkbook } from './core/template';
 import { EDITABLE_FIELDS, FIELD_LABELS, overrideKeys, pendingKeys, revertDraft, type EditableKey, type PierValues } from './core/changes';
 import { adjustRow, layoutText, resolveRowCounts, rowLayout, totalPiles } from './core/piles';
-import { applyCopy, COPY_ITEMS, DEFAULT_COPY_ITEMS, planCopy, type CopyItem } from './core/copy';
-import { copyCandidates, copyItemsFor, selectedTargets, type CopyCandidate } from './core/copy-targets';
+import { applyCopy, COPY_ITEMS, planCopy, type CopyItem } from './core/copy';
+import { copyCandidates, copyItemsFor, copyItemsWithOverrides, selectedTargets, type CopyCandidate } from './core/copy-targets';
 import { pileGeometry } from './core/geometry';
 import { rebarSummary, type RebarRow } from './core/rebar/summary';
 import { shearSegments } from './core/rebar/coping';
@@ -649,11 +649,18 @@ function chosenCopyItems(): CopyItem[] {
   return copyItemsFor(state.member).filter((item) => copyItemChoice.has(item));
 }
 
-/** The items ticked by the user; kept across 부재 changes. */
-let copyItemChoice = new Set<CopyItem>(DEFAULT_COPY_ITEMS);
+/** The items ticked by the user. Reset to the 기준 pier's changed items when the 기준 pier or 부재 changes. */
+let copyItemChoice = new Set<CopyItem>();
+let copyItemKey = '';
 
 /** Shows the copy items of the selected 부재 only. A 부재 without items shows a note instead. */
 function renderCopyItems(): void {
+  const src = activePier();
+  const key = `${src?.input.name ?? ''}|${state.member}`;
+  if (key !== copyItemKey) {
+    copyItemKey = key;
+    copyItemChoice = new Set(src ? copyItemsWithOverrides(src) : []);
+  }
   const box = $('cp-items');
   box.replaceChildren();
   const items = copyItemsFor(state.member);
@@ -3080,6 +3087,12 @@ $<HTMLButtonElement>('cp-select-same').addEventListener('click', () => {
   renderCopyTargets();
   renderCopyPreview();
 });
+$<HTMLButtonElement>('cp-items-reset').addEventListener('click', () => {
+  const src = activePier();
+  copyItemChoice = new Set(src ? copyItemsWithOverrides(src) : []);
+  renderCopyItems();
+  renderCopyPreview();
+});
 $<HTMLButtonElement>('cp-clear').addEventListener('click', () => {
   copySelection = new Set();
   renderCopyTargets();
diff --git a/tests/copy-targets.test.ts b/tests/copy-targets.test.ts
index 63591e7..8b5960d 100644
--- a/tests/copy-targets.test.ts
+++ b/tests/copy-targets.test.ts
@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'vitest';
-import { copyCandidates, copyItemsFor, selectedTargets, type CopyCandidate } from '../src/core/copy-targets';
+import { copyCandidates, copyItemsFor, copyItemsWithOverrides, selectedTargets, type CopyCandidate } from '../src/core/copy-targets';
+import { loadP1 } from './helpers';
 
 const piers: CopyCandidate[] = [
   { name: 'P1', type: 'T형', hasModel: true },
@@ -63,3 +64,24 @@ describe('copyItemsFor (부재 선택에 해당하는 복사 항목)', () => {
     expect([...all].sort()).toEqual(['coping-length', 'coping-width', 'ground-position', 'pile-length', 'pile-rows']);
   });
 });
+
+describe('copyItemsWithOverrides (기준 교각에서 되돌리기가 표시된 항목)', () => {
+  const base = loadP1();
+  const source = (draft: Partial<typeof base>) => ({ defaults: base, input: base, draft: { ...base, ...draft } });
+
+  it('is empty when the 기준 pier has no changed values', () => {
+    expect(copyItemsWithOverrides(source({}))).toEqual([]);
+  });
+
+  it('selects the item of a changed coping length', () => {
+    expect(copyItemsWithOverrides(source({ copingLengthMm: base.copingLengthMm + 500 }))).toEqual(['coping-length']);
+  });
+
+  it('selects the pile item when the pile length changed', () => {
+    expect(copyItemsWithOverrides(source({ pileLengthMm: base.pileLengthMm + 100 }))).toEqual(['pile-length']);
+  });
+
+  it('ignores a changed value that no copy item carries (groundEl)', () => {
+    expect(copyItemsWithOverrides(source({ groundEl: base.groundEl + 0.5 }))).toEqual([]);
+  });
+});