尝试这个-

$('select').on('change', function() {

  alert( this.value );

});


<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>



<select>

    <option value="1">One</option>

    <option value="2">Two</option>

</select>

您还可以参考 onchange 事件-

function getval(sel)

{

    alert(sel.value);

}


<select onchange="getval(this);">

    <option value="1">One</option>

    <option value="2">Two</option>

</select>