html

<script src="http://apps.bdimg.com/libs/jquery/1.11.1/jquery.min.js"></script>
<ul class="navWrap">
	<li class="current"><a href="#item1">1樓</a></li>
	<li><a href="#item2">2樓</a></li>
	<li><a href="#item3">3樓</a></li>
	<li><a href="#item4">4樓</a></li>
	<li><a href="#item5">5樓</a></li>
</ul>
<ul class="floorWrap">
	<li id="item1" class="item">一樓內容</li>
	<li id="item2" class="item">二樓內容</li>
	<li id="item3" class="item">三樓內容</li>
	<li id="item4" class="item">四樓內容</li>
	<li id="item5" class="item">五樓內容</li>
</ul>
 

css

html * {font-family:"Microsoft YaHei","tahoma ","Arial",;}
	html, body, div, span, applet, object, iframe,h1, h2, h3, h4, h5, h6, p, blockquote, pre,a, abbr, acronym, address, big, cite, code,del, dfn, em, font, img, ins, kbd, q, s, samp,small,
	strike, strong, sub, sup, tt, var,dl, dt, dd, ol, ul, li,fieldset, form, label, legend,table, caption, tbody, tfoot, thead, tr, th, td
	{margin:0;padding:0;border:none;font-weight:inherit;font-style:inherit;}
	li{list-style: none;}
	.navWrap{width: 100px;height: 200px;position: fixed;left: 50%;top: 100px; margin-left:250px;border: #666 solid 1px;}
	.navWrap li{width: 100px;height: 40px;text-align: center;line-height: 40px;}
	.navWrap li a{color:#000;text-decoration: none;display: block;}
	.floorWrap{width:500px;margin:0 auto;}
	.floorWrap li{height: 600px;text-align: center;line-height: 600px;border: 1px solid red;}
	.current{background-color: #908CC8;}
	.current a{color:#fff;}
 

javascript

$(window).on("scroll",function(){
		var scrollTop = $(document).scrollTop();
		var floor = $('.floorWrap');
		var nav = $('.navWrap').find('li');
		var items = $('.floorWrap').find('.item');

		items.each(function(){
			var m=$(this);
			var itemTop = m.offset().top;
			if(scrollTop>itemTop-200){
				console.log(scrollTop-itemTop);
				nav.eq(m.index()).addClass('current').siblings().removeClass('current');
			}else{
				return false;
			}
		})
	})
 

想讓樓層有滑動效果的話加上這個函式（去掉HTML程式碼裡的錨點）

$(".navWrap li").on("click",function(){
		var m=$(this);
		var nav = $('.navWrap').find("li");
		var floor = $(".floorWrap").find("li");
		var floorOffsetTop = floor.eq(m.index()).offset().top;
		$("body,html").animate({
			"scrollTop":floorOffsetTop
		},500)
	})