<html><head><script src="https://libs.baidu.com/jquery/2.1.4/jquery.min.js"></script><script>$(document).ready(function(){ $("#btn1").click(function(){ $("p").wrap("<div></div>"); }); $("#btn2").click(function(){ $("p").unwrap(); });});</script><style>div{background-color: yellow;}</style></head><body><p>This is a paragraph.</p><p>This is another paragraph.</p><button id="btn1">Wrap a div element around each p element</button><button id="btn2">Unwrap</button></body></html>