x
 
<!DOCTYPE html>
<html>
<body>
<div id="div1">
<p id="p1">这是一段文字。</p>
<p id="p2">这是另一段文字。</p>
</div>
<script>
var para = document.createElement("p");
var node = document.createTextNode("这是新的文本。");
para.appendChild(node);
var element = document.getElementById("div1");
var child = document.getElementById("p1");
element.insertBefore(para,child);
</script>
</body>
</html>