哈哈，试了这么多还是encodeURIComponent管用啊！！！！

在汉字的位置加个保护措施：encodeURIComponent(parentid)

function loadCity(parentid) {              var city = '${hotel.city}';                               $.ajax({                     url: './listCity.jspx?prov='+ encodeURIComponent(parentid),                     type: 'GET',                     dataType: 'JSON',                     timeout: 5000,                     error: function() { alert('加载城市列表失败!'); },                     success: function(msg) {                         $("#city").empty();                         $.each(eval(msg), function(i, item) {                          if(item.city ==city){                              $("
    
     " + item.city + "").appendTo($("#city"));                          }else{                               $("
     
      " + item.city + "").appendTo($("#city"));                          }                                                                              });                     }                 });             }
     
    

网上说的另一种加contentType的方法貌似不管用，o(︶︿︶)o 唉，还是自己靠谱啊~~

contentType: 'application/x-www-form-urlencoded; charset=utf-8',