<p>A mobile locating system is provided, which comprises: a service requesting device for sending a service request including specific position information to a locating device; the locating device comprising a position service unit and a sending unit. The position service unit is used to obtain the user identifications corresponding to said specific position information; the sending unit is used to send said user identifications to said service requesting device; and the service requesting device is also used to receive said user identifications from said locating device. The system is able to provide the users as well as the user identifications within a region of the geographical position represented by the specific position information on the basis of mobile locating. A service requesting device, a locating device and a method thereof are also provided.</p>
