/* 1 (?s) 代表 Pattern.DOTALL,也就是匹配换行，允许 img里出现在多行 2 .*?代表非贪婪匹配任意字符，直到后面的条件出现 3 ?: 代表这个匹配但不被捕获，也就是不在结果出现 [\.gif|\.jpg] 是或者的意思 */ $pattern="/<img.*?src=[\'|\"](.*?(?:[\.gif|\.jpg]))[\'|\"].*?[\/]?>/"; $str='<p style="padding: 0px; margin-top: 0px; margin-bottom: 0px; line-height: 200%;"><img border="0" src="upfiles/2009/07/1246430143_4.jpg" alt=""/></p><p style="padding: 0px; margin-top: 0px; margin-bottom: 0px; line-height: 200%;"><img border="0" src="upfiles/2009/07/1246430143_3.jpg" alt=""/></p><p style="padding: 0px; margin-top: 0px; margin-bottom: 0px; line-height: 200%;"><img border="0" src="upfiles/2009/07/1246430143_1.jpg" alt=""/></p>'; preg_match_all($pattern,$str,$match); print_r($match); /* Array ( [0] => Array ( [0] => <img border="0" src="upfiles/2009/07/1246430143_4.jpg" alt=""/> [1] => <img border="0" src="upfiles/2009/07/1246430143_3.jpg" alt=""/> [2] => <img border="0" src="upfiles/2009/07/1246430143_1.jpg" alt=""/> ) [1] => Array ( [0] => upfiles/2009/07/1246430143_4.jpg [1] => upfiles/2009/07/1246430143_3.jpg [2] => upfiles/2009/07/1246430143_1.jpg ) ) */