Abstract: WT5HZAbstract 〓WTThis paper presents a method to determine the position of unknown radio source based on signal strength，which obtained by vehicle monitoring system.In order to eliminate the influence of Non Line of Sight（NLOS)propagation，the local average signal method and the wavelet analysis are introduced to eliminate the multipath fading noise and the shadow fading noise.Based on the tested data，a radio propagation model with new a factor is promoted.The factor could compensate the deviation automatically. according to the different environment By computing the target equation of residual error iteratively with genetic algorithm，the radio source location is accurately. achieved The computer simulation and the measured experiment shows the effectiveness of this algorithm.