Non-Line of Sight (NLOS) error due to the blockage of direct paths has been considered as the major problem in the wireless localization. Therefore, this paper studies the influence on different algorithms caused by the same NLOS error in order to identify LOS base stations (BS) from NLOS BS. Specifically, Time of Arrival (TOA) based algorithm and Time Sum of arrival (TSOA) based algorithm are chosen to be the two different localization algorithms to detect the LOS BS in this paper. Simulations show that the proposed strategy presents superior performance in Dense NLOS environment.