<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>更改iframe内容</title> <script> function changeStyle(){ var x=document.getElementById("myframe"); var y=(x.contentWindow || x.contentDocument); if (y.document)y=y.document; y.body.style.backgroundColor="#0000ff"; // 这种是一起写法 document.getElementById("myframe").contentWindow.document.body.style.backgroundColor="#00304f"; } </script> </head> <body> <iframe id="myframe" src="demo_iframe.htm"> <p>你的浏览器不支持iframes。</p> </iframe> <br><br> <input type="button" onclick="changeStyle()" value="修改背景颜色"> </body> </html>