得到当前分类的子分类，具体的代码如下，可以快速的得到
<?php   
 
    $category_model = Mage::getModel('catalog/category'); //get category model
 
    $_category = $category_model->load($categoryid); //$categoryid for which the child categories to be found       
 
        $all_child_categories = $category_model->getResource()->getAllChildren($_category); //array consisting of all child categories id
 
?>
 $all_child_categorie里面含有当前分类和所有子分类的ID，他是一个数组，OK！