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){
                        		$("<option value='" + item.city + "' selected = 'selected'>" + item.city + "</option>").appendTo($("#city"));
                        	}else{
                        		 $("<option value='" + item.city + "'>" + item.city + "</option>").appendTo($("#city"));
                        	}
                        
                           
                        });
                    }
                });
            }

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