<?php
$html = '<ul><li>《mainGood》《mainGood》</li><li>《subGood》《subGood》《subGood》</li></ul>';
echo preg_replace("/(《mainGood》|《subGood》)/eis","foo('$1')",$html);

function foo($v){
    global $count;
    if($v=='《mainGood》'){
        return 1;
    }else{
        $count++;
        return $count+1;
    }
}
//<ul><li>11</li><li>234</li></ul>

------解决方案--------------------

$num_mainGood = $num_subGood = 0;
echo preg_replace_callback("/(《mainGood》)|(《subGood》)/is", '回调函数', $html);

function 回调函数($r) {
 global $num_mainGood, $num_subGood;
 if($r[1]) $num_mainGood++;
 if($r[2]) $num_subGood++;
 //以下写返回内容的代码

}


------解决方案--------------------

PHP code
[liangdong@bb-browser-test00.vm.baidu.com php_project]$ php main.php 
<ul><li>a</li><li>bc</li></ul>
[liangdong@bb-browser-test00.vm.baidu.com php_project]$ cat main.php 
<?php
$html = <<<EOF
<ul><li>《mainGood》</li><li>《subGood》《subGood》</li></ul>
EOF;

$count = 0;
$map = array(0 => 'a', 1 => 'b', 2 => 'c');
$result = preg_replace_callback('/《mainGood》|《subGood》/i', 
                function($match) {
                        global $count;
                        global $map;
                        return $map[$count++];
                }, $html);
echo $result . PHP_EOL;
?>