$(function() { var $sidebar = $("#sidebar"), $window = $(window), offset = $sidebar.offset(), topPadding = 15; $window.scroll(function() { if ($window.scrollTop() > offset.top) { $sidebar.stop().animate({ marginTop: $window.scrollTop() - offset.top + topPadding }); } else { $sidebar.stop().animate({ marginTop: 0 }); } }); });
进一步:http://css-tricks.com/scrollfollow-sidebar/