Abstract: Currently, nine COMPASS satellites have been launched. Regional positioning system of COMPASS has been constructed. It can supply Chinese users with primary three-dimensional positioning. Mainly work of COMPASS is focused on tests and evaluations. This paper discusses conversion of time and coordinates between COMPASS and GPS, broadcasting ephemeris and calculation of satellite coordinates, and precise positioning with COMPASS and GPS. The united precise positioning with COMPASS and GPS is realized, and proved by test results of observations on Sept. 29, 2011. Our tests and results can supply reference to construction of COMPASS II system. Key words: Global Positioning System; Compass Satellite Navigation System; Fusion Positioning