Abstract: To locate noise-frequency modulation jammer with time difference of arrival(TDOA) in passive systems,a new method of delta-modulation coding jointed cross-correlation is presented.The location accuracy of this method is discussed when the jam-noise ration(JNR) of receiver stations is various.Simulations show that this method possesses the same performance as the cross-correlation one using signal sample data directly.The most advantage of this method is that it can reduce throughputs between passive location receiver stations.