<ul id='ul'> <li> <input type="tel" /> <p>请输入正确的电话号码</p> </li></ul><span>添加</span>* { margin: 0; padding: 0;}ul,li { list-style: none;}ul { padding:10px 20px;}ul li{margin-top:10px;}ul li input { padding: 0 10px; height: 30px; border: 1px solid #ddd;}ul li p { color: red; font-size: 12px; margin-top:5px; display: none;}span { display: block; margin-left: 20px; width: 60px; height: 28px; background: #00A2D4; text-align: center; line-height: 28px; color: #fff; font-size: 14px; cursor: pointer;}$(function(){ $('#ul').on('keyup', 'input', function(){ var v = $(this).val(); if( ! /^1[34578]\d{9}/.test(v) ){ $(this).next().show(); }else{ $(this).next().hide(); } }); $('span').click(function(){ var li=$('#ul li:first').clone(); $('input',li).val(''); $('p', li).hide(); $('#ul').append( li ); });});