<select id="ReviewStatus" name="ReviewStatus"><option selected="selected" value="0">空号</option>
<option value="1">不接</option>
<option value="2">不需要</option>
<option value="3">挂机</option>
<option value="4">黑名单</option>
<option value="5">成功</option>
</select>
 
<textarea class="form-control valid" cols="20" id="ReviewMark" name="ReviewMark" rows="2" style="width:500px;height:100px;"></textarea>

$(function () {   
 
   $("#ReviewMark").val($("#ReviewStatus").find("option:selected").text());
   $("#ReviewStatus").change(function () {
    $("#ReviewMark").val($("#ReviewStatus").find("option:selected").text());
   });
  });