<meta charset="utf-8"> 
<script type="text/javascript" src="js/jquery-1.7.1.min.js"></script> 
<div id="imgs_box"> 
  <ul class="play_imgs_width imgs_source"> 
    <li><a href="javascript:;"><img src="./images/banner1.jpg" idth="610" height="390"/></a></li> 
    <li><a href="javascript:;"><img src="./images/banner1.jpg" idth="610" height="390"/></a></li> 
    <li><a href="javascript:;"><img src="./images/banner1.jpg" idth="610" height="390"/></a></li> 
  </ul> 
  <ul class="imgs_buttons play_imgs_width"> 
    <li><a href="" class="buttons_ahover">1</a></li> 
    <li><a href="" class="buttons_default">2</a></li> 
    <li><a href="" class="buttons_default">3</a></li> 
  </ul>  
  <ul class="test"> 
    <li> 
      <ul class="test_first_child"> 
        <li></li> 
        <li></li> 
        <li></li> 
        <li></li> 
      </ul> 
    </li> 
  </ul>  
</div> 

//获取imgs_box下的所有元素 
$(function(){ 
  $('#imgs_box a').each(function(){ 
    console.log(this); 
  }); 
}); 

$(function(){ 
  $('#imgs_box > ul').each(function(){ 
    console.log(this); 
  }); 
}); 

$(function(){ 
  $('.imgs_source + ul').each(function(){ 
    console.log(this); 
  }); 
}); 

$(function(){ 
  $('.imgs_source ~ ul').each(function(){ 
    console.log(this); 
  }); 
});