Abstract: According to the characteristic of bandpass signal,a beamforming method by extraction of complex envelope is proposed This method contains three necessary processes to obtain complex envelope beam signals,namely,down conversion to in-phase and quadrature,phase rotation of in-phase and quadrature,time delay and sum of in-phase and quadrature after phase rotation.Then,the beam in the direction of an incidence angle is formed.The method can efficiently reduce the sampling rate and the complexity of digital processing.