Abstract: HF is a media with serious selective fade.Its minimal characterization is provided by the gross channel parameters of multipath spread (M) and Doppler spread(D).CHIRP modem is a new type of HF modem using low-rate phase modulation and has high reliability and robustness of data transmission.This paper introduces the technique to estimate M and D with CHIRP modem.And a scheme of spreading the maximum M that can be estimated is also discussed.The result of simulation proves that techniques for measurement of M and D are simple but efficient and accurate.