<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-1.9.1.js'></script>
<script type='text/javascript'>
$(function(){
var yourList = $("ul li");
var len = yourList.length;
yourList.filter(':gt('+ ((len/2) - 1) +')').css('color','red');
});
</script>
</head>
<body>
<ul>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
</ul>
</body>
</html>