Abstract: This paper presents and analyzes a constant modulus algorithm (CMA) adaptive beamforming algorithm which is based on conjugate gradient method. This algorithm focuses on a new technique for data block modificatory method with conjugate gradient, and overcomes the shortcoming of traditional CMA algorithms, such as slow convergence speed or vast complexity. An analysis is given to find the misadjustments performance in MCG-CMA algorithm with different sampling length. Computer simulations show that the algorithm has better convergence performance and better signal to interference plus noise ratio (SINR) capability than LS-CMA and SCG-CMA algorithm.