$(document).ready(function(){
$(document).mousemove(function(event){
$('#mouseFollow').offset({left:event.pageX,top:event.pageY-10});
});
});
<html>
<head>
<link rel="stylesheet" type="text/css" href="style.css"/>
<script src="script.js"></script>
</head>
<body>
<div id="mouseFollow"></div>
</body>
</html>
#mouseFollow{
background-color: red;
height: 20px;
width: 20px;
}