pdf.addHTML($("seçici"),function() {
//işlemler
});
<!DOCTYPE HTML>
<html lang="en-US">
<head>
<meta charset="UTF-8">
<title>UstaDerslik</title>
<script type="text/javascript" src="jquery-1.11.1.min.js"></script>
<script type="text/javascript" src="jspdf.min.js"></script>
<script type="text/javascript" src="html2canvas.js"></script>
<script type="text/javascript">
$(function(){
var pdf = new jsPDF('p','pt','a4');
pdf.addHTML($("#pdf"),function() {
var yazdir = pdf.output('datauristring');
$('#onizleme').attr("src",yazdir);
});
})
</script>
<style type="text/css">
#pdf{width:100%;height:500px;background:#f1f1f1;position:absolute;left:0;top:0;z-index:-10;text-align:center;}
#pdf p{font-size:25px;}
.kutu{width:200px;height:200px;background:firebrick;margin-left:150px;float:left;}
</style>
</head>
<body>
<iframe id="onizleme" type="application/pdf" style="width:100%;height:900px;" frameborder="0"></iframe>
<div id="pdf">
<h1>sdfdsfdsf</h1>
<p>sadsadasdsadasdsadasd dasdsd asd asd asd asdas dsadasddas sadasd</p>
<div class="kutu"></div>
<div class="kutu"></div>
<div class="kutu"></div>
</div>
</body>
</html>