sample: jQuery $.append / $.appendTo

HTML

<div class="post"><p class="id">id</p><span class="name">name</span><p class="time">time</p></div>

<div id="result"></div>

CSS

#result {
  border: 1px solid;
}

JavaScript

var content = "コンテンツ";
$(".post").append("<p>" + content + "</p>").appendTo("#result");