Abstract: A new non-line-of-sight location algorithm based on TDOA for mobile station is developed in this paper. One of the advantages of this method is that no statistical models or prior information on NLOS channel condition are needed. Simulation and comparison of performance with other existing methods have shown the effectiveness of NLOS error mitigation in location estimate. Its good characteristics including low requirement, non-iteration, very low computational complexity make it easily available to apply to practice.