Sibling by class name
<html> <head> <script type='text/javascript' src='js/jquery-1.3.2.js'></script> <script type='text/javascript'> var tmpExample = { ready : function() { $('ul#uiID li.liClassName3').siblings('.liClassName').addClass('mySiblings'); } }; $(document).ready(tmpExample.ready); </script> <style type='text/css'> ul#uiID { list-style: none; margin: 0; padding: 0; } ul#uiID li { margin: 1px; padding: 3px; } li.mySiblings{ background: khaki; } </style> </head> <body> <ul id='uiID'> <li>A</li> <li class='liClassName'>B</li> <li class='liClassName'>C</li> <li>D</li> <li class='liClassName2'>E</li> <li>F</li> <li class='liClassName3'>G</li> </ul> </body> </html>