<form action="#" name="myform">

        <label>省</label><select name="provice" id="provice"><option value="-1">请输入省份</option></select>

        <label>市</label><select name="city" id="city"><option value="-1">请输入城市</option></select>

        <label>县</label><select name="locale" id="locale"><option value="-1">请输入区县</option></select>

    </form>  

    var jsonData = [{

        treeNode : '请输入省份',

        value : -1,

        childNode : [{

        treeNode : '请输入城市',

        value : -1,

        childNode : [{

                treeNode : '请输入区县',

            value : -1,

            childNode : []

        }]

        }]

    },{

        treeNode : '北京',

        value : 1,

        childNode : [{

        treeNode : '东城区',

        value : 11,

        childNode : []

        },{

        treeNode : '西城区',

        value : 12,

        childNode : []

        }]

    },{

        treeNode : '广西壮族自治区',

        value : 2601,

        childNode : [{

        treeNode : '南宁',

        value : 6653,

        childNode : [{

            treeNode : '横县',

            value : 10799,

            childNode : []

        }, {

            treeNode : '宾阳县',

            value : 10800,

            childNode : []

            }]

        }]

    }]  

    function initCountry(){

        var provice = $("#provice");

        var city = $("#city");

        var locale = $("#locale");

        var proviceStr = "";

        $.each(<span style="color:#FF0000;">jsonData</span>,function(index,items){

            proviceStr += "<option value='"+jsonData[index].value+"'>"+jsonData[index].treeNode+"</option>";

        });

        provice.empty().append(proviceStr);

        provice.bind("change",function(){

            if($(this).find(":selected").attr("value") == -1){

                city.empty().append("<option value='-1'>请输入区县</option>");

            }

        });

        provice.bind("change",function(){

            var cityStr = '';

            var index = provice.find(":selected").index();

            $.each(jsonData[index].childNode,function(index,items){

                city.empty();

                cityStr += "<option value='"+items.value+"'>"+items.treeNode+"</option>";

                city.append(cityStr);

            })

            changeLocale();

        });

        city.bind("change",changeLocale);

        function changeLocale(){

            var localeStr = '';

            var index = provice.find(":selected").index();

            var index2 = city.find(":selected").index();

            $.each(jsonData[index].childNode[index2].childNode,function(index,items){

                locale.empty();

                localeStr += "<option value='"+items.value+"'>"+items.treeNode+"</option>";

                locale.append(localeStr);

            })

            if(localeStr == ''){

                locale.empty();

                locale.append("<option value='-11'>请输入区县</option>");

            }

        }

    }

    $(function(){

        initCountry();  

    })