diff --git a/packages/util/package.json b/packages/util/package.json
index 53052dd..75f41db 100644
--- a/packages/util/package.json
+++ b/packages/util/package.json
@@ -22,6 +22,9 @@
   "homepage": "https://github.com/idrawjs/idraw#readme",
   "author": "chenshenhai",
   "license": "MIT",
+  "devDependencies": {
+    "@idraw/types": "^0.2.0-alpha.16"
+  },
   "publishConfig": {
     "access": "public"
   }
diff --git a/packages/util/src/index.ts b/packages/util/src/index.ts
index 9f3b022..268159d 100644
--- a/packages/util/src/index.ts
+++ b/packages/util/src/index.ts
@@ -5,6 +5,7 @@ import { createUUID } from './lib/uuid';
 import { deepClone } from './lib/data';
 import istype from './lib/istype';
 import { loadImage, loadSVG, loadHTML } from './lib/loader';
+import Context from './lib/context';
 
 export default {
   time: {
@@ -31,5 +32,6 @@ export default {
   istype,
   data: {
     deepClone,
-  }
+  },
+  Context,
 };
\ No newline at end of file
diff --git a/packages/util/src/lib/context.ts b/packages/util/src/lib/context.ts
new file mode 100644
index 0000000..c9aa298
--- /dev/null
+++ b/packages/util/src/lib/context.ts
@@ -0,0 +1,282 @@
+import { TypeContext, TypeBoardSizeOptions } from '@idraw/types';
+
+type Options = {
+  width: number;
+  height: number;
+  contextWidth: number;
+  contextHeight: number;
+  devicePixelRatio: number;
+}
+
+type Transform = {
+  scale?: number;
+  scrollX?: number;
+  scrollY?: number;
+}
+
+type PrivateTransform = {
+  scale: number;
+  scrollX: number;
+  scrollY: number;
+}
+
+class Context implements TypeContext {
+  private _opts: Options;
+  private _ctx: CanvasRenderingContext2D;
+  private _transform: PrivateTransform; 
+
+  // private _scale: number;
+  // private _scrollX: number;
+  // private _scrollY: number;
+
+  constructor(ctx: CanvasRenderingContext2D, opts: Options) {
+    this._opts = opts;
+    this._ctx = ctx;
+    this._transform = {
+      scale: 1,
+      scrollX: 0,
+      scrollY: 0,
+    };
+  }
+
+  resetSize(opts: TypeBoardSizeOptions) {
+    this._opts = {...this._opts, ...opts};
+  }
+
+  calcDeviceNum(num: number): number {
+    return num * this._opts.devicePixelRatio;
+  }
+
+  calcScreenNum(num: number): number {
+    return num / this._opts.devicePixelRatio;
+  }
+
+  getSize() {
+    return  {
+      width: this._opts.width,
+      height: this._opts.height,
+      contextWidth: this._opts.contextWidth,
+      contextHeight: this._opts.contextHeight,
+      devicePixelRatio: this._opts.devicePixelRatio,
+    };
+  }
+
+  setTransform(config: Transform) {
+    this._transform = {...this._transform, ...config};
+  }
+
+  getTransform() {
+    return {
+      scale: this._transform.scale,
+      scrollX: this._transform.scrollX,
+      scrollY: this._transform.scrollY,
+    };
+  }
+
+  setFillStyle(color: string | CanvasPattern | CanvasGradient) {
+    this._ctx.fillStyle = color;
+  }
+
+  fill(fillRule?: CanvasFillRule | undefined) {
+    return this._ctx.fill(fillRule || 'nonzero');
+  }
+
+  arc(x: number, y: number, radius: number, startAngle: number, endAngle: number, anticlockwise?: boolean | undefined): void {
+    return this._ctx.arc(this._doSize(x), this._doSize(y), this._doSize(radius), startAngle, endAngle, anticlockwise);
+  }
+
+  rect(x: number, y: number, w: number, h: number) {
+    return this._ctx.rect(this._doSize(x), this._doSize(y), this._doSize(w), this._doSize(h));
+  }
+  
+  fillRect(x: number, y: number, w: number, h: number) {
+    return this._ctx.fillRect(
+      this._doSize(x), 
+      this._doSize(y),
+      this._doSize(w),
+      this._doSize(h)
+    );
+  }
+
+  clearRect(x: number, y: number, w: number, h: number) {
+    return this._ctx.clearRect(
+      this._doSize(x), 
+      this._doSize(y),
+      this._doSize(w),
+      this._doSize(h)
+    );
+  }
+
+  beginPath() {
+    return this._ctx.beginPath();
+  }
+
+  closePath() {
+    return this._ctx.closePath();
+  }
+
+  lineTo(x: number, y: number) {
+    return this._ctx.lineTo(this._doSize(x), this._doSize(y));
+  }
+
+  moveTo(x: number, y: number) {
+    return this._ctx.moveTo(this._doSize(x), this._doSize(y));
+  }
+
+  arcTo(x1: number, y1: number, x2: number, y2: number, radius: number): void {
+    return this._ctx.arcTo(this._doSize(x1), this._doSize(y1), this._doSize(x2), this._doSize(y2), this._doSize(radius));
+  }
+
+  setLineWidth(w: number) {
+    return this._ctx.lineWidth = this._doSize(w);
+  }
+
+  setLineDash(nums: number[]) {
+    return this._ctx.setLineDash(nums.map(n => this._doSize(n)));
+  }
+
+  isPointInPath(x: number, y: number) {
+    return this._ctx.isPointInPath(this._doX(x), this._doY(y));
+  }
+
+  isPointInPathWithoutScroll(x: number, y: number) {
+    return this._ctx.isPointInPath(this._doSize(x), this._doSize(y));
+  }
+
+  setStrokeStyle(color: string) {
+    this._ctx.strokeStyle = color;
+  }
+
+  stroke() {
+    return this._ctx.stroke();
+  }
+
+  translate(x: number, y: number) {
+    return this._ctx.translate(this._doSize(x), this._doSize(y));
+  }
+  
+  rotate(angle: number) {
+    return this._ctx.rotate(angle);
+  }
+
+  drawImage(...args: any[]) {
+    const image: CanvasImageSource = args[0];
+    const sx: number = args[1];
+    const sy: number = args[2];
+    const sw: number = args[3];
+    const sh: number = args[4];
+
+    const dx: number = args[args.length - 4];
+    const dy: number = args[args.length - 3];
+    const dw: number = args[args.length - 2];
+    const dh: number = args[args.length - 1];
+
+    if (args.length === 9) {
+      return this._ctx.drawImage(image, this._doSize(sx), this._doSize(sy), this._doSize(sw), this._doSize(sh), this._doSize(dx), this._doSize(dy), this._doSize(dw), this._doSize(dh));
+    } else {
+      return this._ctx.drawImage(image,this._doSize(dx), this._doSize(dy), this._doSize(dw), this._doSize(dh));
+    }
+  }
+
+  createPattern(image: CanvasImageSource, repetition: string | null): CanvasPattern | null {
+    return this._ctx.createPattern(image, repetition);
+  }
+
+  measureText(text: string): TextMetrics {
+    return this._ctx.measureText(text);
+  }
+
+  setTextAlign(align: CanvasTextAlign): void {
+    this._ctx.textAlign = align;
+  }
+
+  fillText(text: string, x: number, y: number, maxWidth?: number | undefined): void {
+    if (maxWidth !== undefined) {
+      return this._ctx.fillText(text, this._doSize(x), this._doSize(y), this._doSize(maxWidth));
+    } else {
+      return this._ctx.fillText(text, this._doSize(x), this._doSize(y));
+    }
+  }
+
+  strokeText(text: string, x: number, y: number, maxWidth?: number | undefined): void {
+    if (maxWidth !== undefined) {
+      return this._ctx.strokeText(text, this._doSize(x), this._doSize(y), this._doSize(maxWidth));
+    } else {
+      return this._ctx.strokeText(text, this._doSize(x), this._doSize(y));
+    }
+  }
+
+  setFont(opts: { fontSize: number, fontFamily?: string, fontWeight?: 'bold' }): void {
+    const strList: string[] = [];
+    if (opts.fontWeight === 'bold') {
+      strList.push(`${opts.fontWeight}`);
+    }
+    strList.push(`${this._doSize(opts.fontSize || 12)}px`);
+    strList.push(`${opts.fontFamily || 'sans-serif'}`);
+    this._ctx.font = `${strList.join(' ')}`;
+    // console.log('this._ctx.font =',this._ctx.font);
+  }
+
+  setTextBaseline(baseline: CanvasTextBaseline): void {
+    this._ctx.textBaseline = baseline;
+  }
+
+  setGlobalAlpha(alpha: number): void {
+    this._ctx.globalAlpha = alpha;
+  }
+
+  save() {
+    this._ctx.save();
+  }
+  
+  restore() {
+    this._ctx.restore();
+  }
+
+  scale(ratioX: number, ratioY: number) {
+    this._ctx.scale(ratioX, ratioY);
+  }
+
+  setShadowColor(color: string): void {
+    this._ctx.shadowColor = color;
+  }
+
+  setShadowOffsetX(offsetX: number): void {
+    this._ctx.shadowOffsetX = this._doSize(offsetX);
+  }
+
+  setShadowOffsetY(offsetY: number): void {
+    this._ctx.shadowOffsetY = this._doSize(offsetY);
+  }
+
+  setShadowBlur(blur: number): void {
+    this._ctx.shadowBlur = this._doSize(blur);
+  }
+
+  ellipse(
+    x: number,y: number, radiusX: number, radiusY: number,
+    rotation: number, startAngle: number, endAngle: number, counterclockwise?: boolean | undefined
+  ) {
+    this._ctx.ellipse(this._doSize(x), this._doSize(y), this._doSize(radiusX), this._doSize(radiusY), rotation, startAngle, endAngle, counterclockwise)
+  }
+
+  private _doSize(num: number) {
+    return this._opts.devicePixelRatio * num;
+  }
+
+  private _doX(x: number) {
+    const { scale, scrollX } = this._transform;
+    const _x = (x - scrollX) / scale;
+    return this._doSize(_x);
+  }
+
+  private _doY(y: number) {
+    const { scale, scrollY } = this._transform;
+    const _y = (y - scrollY) / scale;
+    return this._doSize(_y);
+  }
+  
+
+}
+
+export default Context;
\ No newline at end of file