Currently, LBS (Location-based Services) as a new emerging business which is based on mobile communication network is becoming more and more popular. However domestic industry is lack of perfect location service platform and standards because of the complexity and large scale of LBS. Aimed at the cases, the architecture of mobile location service (MLS) platform based on OpenLS (OpenGIS® Location Services) standards is constructed in the paper, and makes it accord with the international standard. Moreover GIS (Geographic Information System) middleware model is also proposed in the paper. We encapsulate the secondary location algorithm and path navigation algorithm into GIS middleware and present four standard interfaces, which could support distributed management and improves the portability of the platform.