list-style

значения свойства:

css/style.css

#u1 {
 list-style: circle;
}

index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
<link href="css/style.css" rel="stylesheet" />
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
</head>
<body>
<ul id="u1">
<li>one</li>
<li>two</li>
<li>three</li>
</ul>
<ul id="u2">
<li>one</li>
<li>two</li>
<li>three</li>
</ul>
<ul id="u3">
<li>one</li>
<li>two</li>
<li>three</li>
</ul>
<script>
/*JavaScript*/
document.getElementById("u2").style.listStyle = "square inside";
/*jQuery*/
$(document).ready(function () {
$("#u3").css({ "list-style": "upper-roman" });
});
</script>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
<link href="css/style.css" rel="stylesheet" />
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
</head>
<body>
<ul id="u1">
<li>one</li>
<li>two</li>
<li>three</li>
</ul>
<ul id="u2">
<li>one</li>
<li>two</li>
<li>three</li>
</ul>
<ul id="u3">
<li>one</li>
<li>two</li>
<li>three</li>
</ul>
<script>
/*JavaScript*/
document.getElementById("u2").style.listStyle = "square inside";
/*jQuery*/
$(document).ready(function () {
$("#u3").css({ "list-style": "upper-roman" });
});
</script>
</body>
</html>