Abstract: As a result of interaction between the spacecraft and the charged particles in plasma environment，the surface charging inevitability occurs. On the back grounded dielectric material，there exists a potential difference between the upper surface and the grounded back surface. The surface potential plays an important role in charging and discharging effects. Discharging occurs if the generated electric fields exceed the breakdown threshold. Taking a comprehensive consideration of the plasma particles mass，temperature and density，the secondary electron effects of the dielectric materials，body leakage current and the flight speed，a general expression for surface potential of back grounded dielectric material in plasma environment is derived using the formula of particles Maxwellian velocity distribution. Consequently，the dependences of the surface potential on each of the parameters are discussed concerning the geosynchronous orbit (GEO) environment，and some useful rules are summarized for the surface charging of back grounded dielectric material immersed in plasma. The method introduced here can facilitate the risk assessment for spacecraft surface charging and provide certain theoretical basis for spacecraft charging protection.