hizlica birseyler yaptim kendin gelistirebilirsin bundan sonrasini

<select id="country">
    <option value="tr">Turkey</option>
    <option value="gb">England</option>
</select>
<select id="cities">
    <option>eskisehir</option>
    <option>istanbul</option>
    <option>ankara</option>
</select>

js

var cities = {
    tr : [
        'eskisehir',
        'istanbul',
        'ankara'
    ],
    gb : [
        'london',
        'chelsea'
    ]    
}

cityUpdate = function(val){
    var data = cities[val],
        target = $('#cities');
    if( data !== undefined ) {
        target.empty();
        $.each(data, function(i,d) {
            target.append("<option>" + d + "</option>");
        })
    }
}
    $(function(){
        $('#country').on('change', function(){
            cityUpdate($(this).val());
        })
    })

ornek

http://jsfiddle.net/salihsagdilek/t1rxrx5g/