A method of selecting a SIM for a location service and a multi-SIM device utilizing the same are disclosed. The method, adopted by a multi-SIM device, includes: acquiring Secure User Plane Location (SUPL) information from a corresponding communications network which each SIM is in connection with; determining which communications network supports a location service based on the SUPL information; and requesting the location service on a SIM that is in connection with the supported communications network.