Abstract: The influence of the characteristic of the improper complex vector on MVDR algorithm is stu-died.After FFT is performed on the received data from array,the column vector in each frequency bin is improper.According tothe characteristic of the pseudo-autocorrelation matrix of the improper complex vector,the extended autocorrelation matrix and the extended steering vector are brought forward.Thereby,a new extended MVDR(ExMVDR) algorithm is presented.Simulation results show that ExMVDR can suppress the side-lobe well and improve the SNR of main lobe about 2dB.