diff --git a/src/editor/core/command/Command.ts b/src/editor/core/command/Command.ts
index 4f6b7d1..2aeff15 100644
--- a/src/editor/core/command/Command.ts
+++ b/src/editor/core/command/Command.ts
@@ -5,6 +5,7 @@ export class Command {
   private static undo: Function
   private static redo: Function
   private static format: Function
+  private static bold: Function
   private static print: Function
 
   constructor(adapt: CommandAdapt) {
@@ -12,6 +13,7 @@ export class Command {
     Command.redo = adapt.redo.bind(adapt)
     Command.print = adapt.print.bind(adapt)
     Command.format = adapt.format.bind(adapt)
+    Command.bold = adapt.bold.bind(adapt)
   }
 
   // 撤销、重做、格式刷、清除格式
@@ -28,6 +30,9 @@ export class Command {
   }
 
   // 字体变大、字体变小、加粗、斜体、下划线、删除线、字体颜色、背景色
+  public executeBold() {
+    return Command.bold()
+  }
 
   // 搜索、打印
   public executePrint() {
diff --git a/src/editor/core/command/CommandAdapt.ts b/src/editor/core/command/CommandAdapt.ts
index 3ac6ee2..df97d9d 100644
--- a/src/editor/core/command/CommandAdapt.ts
+++ b/src/editor/core/command/CommandAdapt.ts
@@ -27,7 +27,7 @@ export class CommandAdapt {
     const { startIndex, endIndex } = this.range.getRange()
     if (startIndex === endIndex) return
     const elementList = this.draw.getElementList()
-    elementList.slice(startIndex, endIndex)
+    elementList.slice(startIndex + 1, endIndex + 1)
       .forEach(el => {
         el.font = ''
         el.color = ''
@@ -39,6 +39,17 @@ export class CommandAdapt {
     this.draw.render({ isSetCursor: false })
   }
 
+  public bold() {
+    const { startIndex, endIndex } = this.range.getRange()
+    if (startIndex === endIndex) return
+    const elementList = this.draw.getElementList()
+    elementList.slice(startIndex + 1, endIndex + 1)
+      .forEach(el => {
+        el.bold = true
+      })
+    this.draw.render({ isSetCursor: false })
+  }
+
   public print() {
     return printImageBase64(this.draw.getDataURL())
   }
diff --git a/src/main.ts b/src/main.ts
index e3675c1..564f561 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -60,7 +60,10 @@ window.onload = function () {
   }
 
   // 字体变大、字体变小、加粗、斜体、下划线、删除线、字体颜色、背景色
-
+  document.querySelector<HTMLDivElement>('.menu-item__bold')!.onclick = function () {
+    console.log('bold')
+    instance.command.executeBold()
+  }
 
   // 搜索、打印
   document.querySelector<HTMLDivElement>('.menu-item__print')!.onclick = function () {