A location-based service system and method, which allows a location-based service server connected with a communication device and a cloud data server to perform registration authorization procedures and service authorization procedures using an international mobile subscriber identity of the communication device that cannot be easily modified or forged in the registration and service modes, so that a user may obtain a specific location-based service result via the communication device, and this distributed authentication technique reduces the risk of data theft while increasing the flexibility and convenience in obtaining services.