//按分隔行查找符合非imgs开头非imgs结尾但是包含imgs的字符串 var str = "imgs.xici.net/_img/emot/panda/7.gif\r\n/b1/upload.temp/IMG_9211_%B8%B1%B1%BE_%B8%B1%B1%BE.jpgimgs\r\n/b1/upload.temp/IMG_9211_%B8%B1%B1%BE_%B8%B1%B1%BE.jpg\r\nhttp://imgs.xici.net/_img/emot/cat/7.gif\r\nIraq fighting"; var regex = /^(?!^imgs.*).+(?=imgs)(?!.*imgs$).+$/gm; var find; while((find = regex.exec(str))!= null){ alert(find[0]); }