demo地址：http://www.51toria.cn/demo/JQplus/jqzoom/

使用的JS：

//**************************************************************
// jQZoom allows you to realize a small magnifier window,close
// to the image or images on your web page easily.
//
// jqZoom version 1.0
// Author Doc. Ing. Renzi Marco(www.mind-projects.it)
// Released on Dec 05 2007
// i'm searching for a job,pick me up!!!
// mail: renzi.mrc@gmail.com
//**************************************************************

(function($){

$.fn.jqueryzoom = function(options){

var settings = {
xzoom: 200, //zoomed width default width
yzoom: 200, //zoomed div default width
offset: 10, //zoomed div default offset
position: "right" //zoomed div default position,offset position is to the right of the image
};

if(options) {
$.extend(settings, options);
}

$(this).hover(function(){


var imageLeft = $(this).get(0).offsetLeft;
var imageRight = $(this).get(0).offsetRight;
var imageTop = $(this).get(0).offsetTop;
var imageWidth = $(this).get(0).offsetWidth;
var imageHeight = $(this).get(0).offsetHeight;

var bigimage = $(this).attr("alt");

if($("div.zoomdiv").get().length == 0){

$(this).after("<div class='zoomdiv'><img class='bigimg' src='"+bigimage+"'/></div>");

}

if(settings.position == "right"){

leftpos = imageLeft + imageWidth + settings.offset;

}else{

leftpos = imageLeft - settings.xzoom - settings.offset;

}

$("div.zoomdiv").css({ top: imageTop,left: leftpos });

$("div.zoomdiv").width(settings.xzoom);

$("div.zoomdiv").height(settings.yzoom);

$("div.zoomdiv").show();


$(document.body).mousemove(function(e){

var bigwidth = $(".bigimg").get(0).offsetWidth;

var bigheight = $(".bigimg").get(0).offsetHeight;

var scaley ='x';

var scalex= 'y';


if(isNaN(scalex)|isNaN(scaley)){

var scalex = Math.round(bigwidth/imageWidth) ;

var scaley = Math.round(bigheight/imageHeight);

}

mouse = new MouseEvent(e);



scrolly = mouse.y - imageTop - ($("div.zoomdiv").height()*1/scaley)/2 ;

$("div.zoomdiv").get(0).scrollTop = scrolly * scaley ;

scrollx = mouse.x - imageLeft - ($("div.zoomdiv").width()*1/scalex)/2 ;

$("div.zoomdiv").get(0).scrollLeft = (scrollx) * scalex ;


});
},function(){
$("div.zoomdiv").hide();
$(document.body).unbind("mousemove");
$(".lenszoom").remove();
$("div.zoomdiv").remove();
});

}

})(jQuery);

function MouseEvent(e) {
this.x = e.pageX
this.y = e.pageY
}

页面调用方法：

jQuery.noConflict();
jQuery(document).ready(function(){
$("img.jqzoom").jqueryzoom();
});