Abstract: This paper uses Trimble Business Center 2.8 data processing software to perform C-Grade GPS control network baseline solution and network adjustment with precision ephemeris and broadcast ephemeris. The GAMIT software is used to load precise ephemeris data for baseline solution, and the adjustment calculation is performed with the COSAGPS software. According to the data obtained with above methods, the influence of different ephemeris solutions on the C-Grade GPS baseline solution and the network adjustment results are analyzed. The results yield that the TBC software can respectively perform C-Grade GPS analysis with both ephemeris, but the accuracy of the baseline solution with the precise ephemeris is slightly high. Thus the appropriate data process strategy should be employed according to the actual situation in fieldwork.