By analyzing the problems of CSPRIT algorithm based on second-order statistics under space correlated Gaussian noise, a new algorithm combining fourth-order cumulant and CSPRIT algorithm is proposed to process one-dimensional signal sources, such as binary phase shift keying (BPSK) and M-ary amplitude shift keying (MASK). DOA estimation and beamforming construction can be achieved simultaneously in this way. Compared to the original CSPRIT algorithm, this improved algorithm based on fourth-order cumulant can depress space correlated Gaussian noise well and get more accurate estimation of signals. The validity of this algorithm is also proved by computer simulation.