Determination of mobile localization with time of arrival (TOA) signal is a requirement in cellular mobile communication. In some of the previous methods, localization with non-line-of-sight (NLOS) paths can lead to large position error. Also for simplicity, in most simulations suppose non stationary actual environments as stationary. This paper proposes (residual test + recursive least square) ((RT+RLS)) that has a good application in non stationary environments. In this algorithm, residual test (RT) that can simultaneously determine the number of line- of-sight (LOS) base stations (BSs) and identify them. In simulation studies, the RT can determine the correct number of LOS-BS over 90% of the time. Then using TOA signals obtain these BSs as input of RLS algorithms and estimate mobile position in high attention and low calculation.