Digital distance relay based on line RL model algorithm is firstly developed successfully in China, which has been used widely for high-voltage transmission line protection. However, it has some limits in being directly used for series compensated line. Thus, a new improved RL model based single-phase ground fault location algorithm for series compensated line is proposed. It is well considered of the effect of non-linear MOV and compensated capacitor on actual reactance of transmission line. Compared with conventional fault location algorithm for series compensated line, it does not need to identify whether SC/MOV is in fault loop, and not need to know the parameters and the operating states of SC/MOV/GAP. Simulation results with EMTDC/PSCAD and Matlab show that the proposed algorithm can obtain more accurate results than conventional fault location algorithms for series compensated transmission lines.