<?php $re = '/((?:ā|á|ǎ|à))|((?:ê|ē|é|ě|è))|((?:ī|í|ǐ|ì))|((?:ō|ó|ǒ|ò))|((?:ū|ú|ǔ|ù))|((?:ǖ|ǘ|ǚ|ǜ|ü))/'; $str = '汉(hàn)语(yǔ)平(píng)阴(yīn)女(nǚ)娥(é) => 汉(han)语(yu)平(ping)阴(yin)女(nü)娥(e)'; $result = preg_replace_callback($re, function($match){ $map = array( 0 => 'a', 1 => 'e', 2 => 'i', 3 => 'o', 4 => 'u', 5 => 'ü', ); for($i = 0; $i <=5; $i++) { if(!empty($match[$i])) { return $map[$i]; } } }, $str); echo $str . "\n"; echo $result;