Some signals, such as in radar system, are transmitted as periodic pulse trains. If more than one pulse train are transmitted over the same communication channel, a problem is to separate them for source identification and extract each pulse train at the receiver. This is known as pulse train deinterleaving. In this paper, we present an approach for deinterleaving the pulse trains and extracting their periods combining the estimation of the frequency of each pulse train by DFT, CDIF/SDIF histogram and Sequence Search technique. Also, we present the result of deinterleaving pulse trains and extracting PRI in the complex environment which multiple signals are interleaved.