diff --git a/components/wysiwyg/Canvas.multigroup.resize.test.tsx b/components/wysiwyg/Canvas.multigroup.resize.test.tsx
new file mode 100644
index 0000000..0442207
--- /dev/null
+++ b/components/wysiwyg/Canvas.multigroup.resize.test.tsx
@@ -0,0 +1,56 @@
+import { describe, it, expect } from 'vitest'
+import { render, fireEvent, waitFor } from '@testing-library/react'
+import { Canvas } from '@/components/wysiwyg/Canvas'
+import type { Frame } from '@/lib/wysiwyg/schema'
+
+function makeFrame(): Frame {
+  return {
+    id: 'f1',
+    width: 400,
+    height: 300,
+    background: '#ffffff',
+    layers: [
+      {
+        id: 'l1',
+        name: 'L1',
+        visible: true,
+        locked: false,
+        objects: [
+          { id: 'o1', type: 'image', x: 20, y: 20, width: 50, height: 40, rotate: 0, zIndex: 0, props: { src: 'x', alt: '' } },
+          { id: 'o2', type: 'image', x: 120, y: 60, width: 80, height: 30, rotate: 0, zIndex: 1, props: { src: 'y', alt: '' } },
+        ],
+      },
+    ],
+  }
+}
+
+describe('WYSIWYG Canvas multigroup resize', () => {
+  it('resizes all selected objects by the same snapped delta when resizing last-selected', async () => {
+    const frame = makeFrame()
+    const { getByTestId } = render(<Canvas frame={frame} />)
+
+    // select o1
+    const obj1 = getByTestId('obj-o1')
+    fireEvent.mouseDown(obj1, { clientX: 25, clientY: 25 })
+    // shift+select o2
+    const obj2 = getByTestId('obj-o2')
+    fireEvent.mouseDown(obj2, { clientX: 125, clientY: 65, shiftKey: true })
+
+    // resize using last-selected (o2) handle
+    const handle2 = getByTestId('resize-handle-o2')
+    const canvas = getByTestId('wysiwyg-canvas')
+
+    // Start at bottom-right corner; move by +7,+9 (snap8 => +8, +8)
+    fireEvent.mouseDown(handle2, { clientX: 200, clientY: 90 })
+    fireEvent.mouseMove(canvas, { clientX: 207, clientY: 99 })
+    fireEvent.mouseUp(canvas)
+
+    const o1 = getByTestId('obj-o1')
+    const o2 = getByTestId('obj-o2')
+
+    await waitFor(() => {
+      expect(o2).toHaveStyle({ width: '88px', height: '40px' })
+      expect(o1).toHaveStyle({ width: '58px', height: '50px' })
+    })
+  })
+})
diff --git a/components/wysiwyg/Canvas.multigroup.rotate.test.tsx b/components/wysiwyg/Canvas.multigroup.rotate.test.tsx
new file mode 100644
index 0000000..dc6b40f
--- /dev/null
+++ b/components/wysiwyg/Canvas.multigroup.rotate.test.tsx
@@ -0,0 +1,77 @@
+import { describe, it, expect } from 'vitest'
+import { render, fireEvent, waitFor } from '@testing-library/react'
+import { Canvas } from '@/components/wysiwyg/Canvas'
+import type { Frame } from '@/lib/wysiwyg/schema'
+
+function makeFrame(): Frame {
+  return {
+    id: 'f1',
+    width: 400,
+    height: 300,
+    background: '#ffffff',
+    layers: [
+      {
+        id: 'l1',
+        name: 'L1',
+        visible: true,
+        locked: false,
+        objects: [
+          { id: 'o1', type: 'image', x: 60, y: 60, width: 50, height: 40, rotate: 0, zIndex: 0, props: { src: 'x', alt: '' } },
+          { id: 'o2', type: 'image', x: 160, y: 60, width: 80, height: 30, rotate: 0, zIndex: 1, props: { src: 'y', alt: '' } },
+        ],
+      },
+    ],
+  }
+}
+
+describe('WYSIWYG Canvas multigroup rotate', () => {
+  it('rotates all selected objects by same snapped angle when rotating last-selected', async () => {
+    const frame = makeFrame()
+    const { getByTestId } = render(<Canvas frame={frame} />)
+
+    // select o1 then shift+select o2 (last-selected o2)
+    fireEvent.mouseDown(getByTestId('obj-o1'), { clientX: 60, clientY: 60 })
+    fireEvent.mouseDown(getByTestId('obj-o2'), { clientX: 160, clientY: 60, shiftKey: true })
+
+    const handle2 = getByTestId('rotate-handle-o2')
+    const canvas = getByTestId('wysiwyg-canvas')
+
+    // start rotate at 0deg and move +16px -> snap to 15deg by default
+    fireEvent.mouseDown(handle2, { clientX: 100, clientY: 50 })
+    fireEvent.mouseMove(canvas, { clientX: 116, clientY: 50 })
+    fireEvent.mouseUp(canvas)
+
+    const o1 = getByTestId('obj-o1')
+    const o2 = getByTestId('obj-o2')
+
+    await waitFor(() => {
+      expect(o2).toHaveStyle({ transform: 'rotate(15deg)' })
+      expect(o1).toHaveStyle({ transform: 'rotate(15deg)' })
+    })
+  })
+
+  it('applies fine rotation delta to all when holding Shift', async () => {
+    const frame = makeFrame()
+    const { getByTestId } = render(<Canvas frame={frame} />)
+
+    // select o1 then shift+select o2 (last-selected o2)
+    fireEvent.mouseDown(getByTestId('obj-o1'), { clientX: 60, clientY: 60 })
+    fireEvent.mouseDown(getByTestId('obj-o2'), { clientX: 160, clientY: 60, shiftKey: true })
+
+    const handle2 = getByTestId('rotate-handle-o2')
+    const canvas = getByTestId('wysiwyg-canvas')
+
+    // start rotate at 0deg, move +7px with Shift -> 7deg (no snap)
+    fireEvent.mouseDown(handle2, { clientX: 100, clientY: 50 })
+    fireEvent.mouseMove(canvas, { clientX: 107, clientY: 50, shiftKey: true })
+    fireEvent.mouseUp(canvas)
+
+    const o1 = getByTestId('obj-o1')
+    const o2 = getByTestId('obj-o2')
+
+    await waitFor(() => {
+      expect(o2).toHaveStyle({ transform: 'rotate(7deg)' })
+      expect(o1).toHaveStyle({ transform: 'rotate(7deg)' })
+    })
+  })
+})
diff --git a/components/wysiwyg/Canvas.tsx b/components/wysiwyg/Canvas.tsx
index bf482e7..6a8ff8a 100644
--- a/components/wysiwyg/Canvas.tsx
+++ b/components/wysiwyg/Canvas.tsx
@@ -33,7 +33,9 @@ export function Canvas({ frame, onChange }: CanvasProps) {
   const selectedId = selectedIds[selectedIds.length - 1] ?? null
   const draggingRef = useRef<{ id: string; startX: number; startY: number; origX: number; origY: number } | null>(null)
   const resizingRef = useRef<{ id: string; startX: number; startY: number; origW: number; origH: number } | null>(null)
+  const resizeGroupRef = useRef<{ ids: string[]; orig: Record<string, { w: number; h: number }> } | null>(null)
   const rotatingRef = useRef<{ id: string; startX: number; startY: number; origDeg: number } | null>(null)
+  const rotateGroupRef = useRef<{ ids: string[]; orig: Record<string, { d: number }> } | null>(null)
   const [showGuides, setShowGuides] = useState(false)
   const [guidePos, setGuidePos] = useState<{ x: number; y: number }>({ x: 0, y: 0 })
   const [marquee, setMarquee] = useState<{
@@ -114,7 +116,7 @@ export function Canvas({ frame, onChange }: CanvasProps) {
     draggingRef.current = { id: o.id, startX: e.clientX, startY: e.clientY, origX: o.x, origY: o.y }
     setShowGuides(true)
     setGuidePos({ x: snap8(o.x), y: snap8(o.y) })
-  }, [])
+  }, [selectedIds, model.layers])
 
   const onMouseMoveCanvas = useCallback((e: React.MouseEvent) => {
     // 마퀴 선택 처리 우선
@@ -148,7 +150,18 @@ export function Canvas({ frame, onChange }: CanvasProps) {
       if (!e.shiftKey) {
         next = Math.round(next / 15) * 15
       }
-      updateObject(rot.id, (o) => ({ ...o, rotate: next }))
+      if (selectedIds.length > 1 && rotateGroupRef.current) {
+        const { ids, orig } = rotateGroupRef.current
+        const base = orig[rot.id]
+        const dd = next - base.d
+        updateObjects(ids, (o) => {
+          const o0 = orig[o.id]
+          if (!o0) return o
+          return { ...o, rotate: o0.d + dd }
+        })
+      } else {
+        updateObject(rot.id, (o) => ({ ...o, rotate: next }))
+      }
       return
     }
     const r = resizingRef.current
@@ -157,7 +170,23 @@ export function Canvas({ frame, onChange }: CanvasProps) {
       const dy = e.clientY - r.startY
       const nw = Math.max(8, snap8(r.origW + dx))
       const nh = Math.max(8, snap8(r.origH + dy))
-      updateObject(r.id, (o) => ({ ...o, width: nw, height: nh }))
+      if (selectedIds.length > 1 && resizeGroupRef.current) {
+        const { ids, orig } = resizeGroupRef.current
+        const base = orig[r.id]
+        const dw = nw - base.w
+        const dh = nh - base.h
+        updateObjects(ids, (o) => {
+          const o0 = orig[o.id]
+          if (!o0) return o
+          return {
+            ...o,
+            width: Math.max(8, o0.w + dw),
+            height: Math.max(8, o0.h + dh),
+          }
+        })
+      } else {
+        updateObject(r.id, (o) => ({ ...o, width: nw, height: nh }))
+      }
       return
     }
     const d = draggingRef.current
@@ -169,7 +198,7 @@ export function Canvas({ frame, onChange }: CanvasProps) {
       setGuidePos({ x: nx, y: ny })
       updateObject(d.id, (o) => ({ ...o, x: nx, y: ny }))
     }
-  }, [updateObject, marquee.active, marquee.x0, marquee.y0, model.layers])
+  }, [updateObject, updateObjects, marquee.active, marquee.x0, marquee.y0, model.layers, selectedIds.length])
 
   const onMouseUpCanvas = useCallback(() => {
     if (marquee.active) {
@@ -177,6 +206,7 @@ export function Canvas({ frame, onChange }: CanvasProps) {
     }
     draggingRef.current = null
     resizingRef.current = null
+    resizeGroupRef.current = null
     rotatingRef.current = null
     setShowGuides(false)
   }, [marquee.active])
@@ -184,12 +214,29 @@ export function Canvas({ frame, onChange }: CanvasProps) {
   const onMouseDownResize = useCallback((e: React.MouseEvent, o: WObject) => {
     e.stopPropagation()
     resizingRef.current = { id: o.id, startX: e.clientX, startY: e.clientY, origW: o.width, origH: o.height }
-  }, [])
+    // capture originals for group resize
+    const ids = Array.from(new Set([...selectedIds, o.id]))
+    const orig: Record<string, { w: number; h: number }> = {}
+    for (const ly of model.layers) {
+      for (const ob of ly.objects) {
+        if (ids.includes(ob.id)) orig[ob.id] = { w: ob.width, h: ob.height }
+      }
+    }
+    resizeGroupRef.current = { ids, orig }
+  }, [selectedIds, model.layers])
 
   const onMouseDownRotate = useCallback((e: React.MouseEvent, o: WObject) => {
     e.stopPropagation()
     rotatingRef.current = { id: o.id, startX: e.clientX, startY: e.clientY, origDeg: o.rotate }
-  }, [])
+    const ids = Array.from(new Set([...selectedIds, o.id]))
+    const orig: Record<string, { d: number }> = {}
+    for (const ly of model.layers) {
+      for (const ob of ly.objects) {
+        if (ids.includes(ob.id)) orig[ob.id] = { d: ob.rotate }
+      }
+    }
+    rotateGroupRef.current = { ids, orig }
+  }, [selectedIds, model.layers])
 
   return (
     <div
@@ -396,7 +443,17 @@ export function Canvas({ frame, onChange }: CanvasProps) {
           if (!selected) return
           const nw = Math.max(8, snap8(typeof width === 'number' ? width : 0))
           const nh = Math.max(8, snap8(typeof height === 'number' ? height : 0))
-          updateObject(selected.id, (o) => ({ ...o, width: nw, height: nh }))
+          if (selectedIds.length > 1) {
+            const dw = nw - selected.width
+            const dh = nh - selected.height
+            updateObjects(selectedIds, (o) => ({
+              ...o,
+              width: Math.max(8, o.width + dw),
+              height: Math.max(8, o.height + dh),
+            }))
+          } else {
+            updateObject(selected.id, (o) => ({ ...o, width: nw, height: nh }))
+          }
         }}
         onRotate={({ rotate, inputEvent }) => {
           if (!selected) return