$("#123 li").first().siblings().children("span").css("color","red")
<ul id="123">
<li>aaaa <span>111</span></li>
<li>aaaa<span>111</span></li>
<li>aaaa<span>111</span></li>
</ul>
$("#div span").not(":first").each(...)
用过滤器not
$("#div span").not(":first").each(...)
$(".createCount").on("click","$("div p").not(":first")",function(){});
$("div p").not(":first")