A location service providing system and method the system includes target SUPL (Secure User Plane for Location) Enabled Terminal (SET) determines and stores a positioning method in an initialization stage of a location service according to a triggered location service request, determines in a location calculation process whether the stored positioning method is available, provides the stored positioning method if it is determined that the stored positioning method is available, and requests for re-determination of a positioning method if it is determined that the stored positioning method is unavailable: and a home-SUPL location platform (H-SLP) which provides the location service using the stored positioning method if the stored positioning method is provided from the target SET or provides the location service by re-determining a positioning method with the target SET if the re-determination of a positioning method is requested.