Abstract: The sparse array with determined elements can increase the array aperture to improve two-dimentional direction-of-arrival(2D-DOA)accuracy,but it brings direction finding ambiguity too.To solve this problem,A sparse coprime L-shaped array and two-dimensional direction finding algorithm based on it are presented.The proposed algorithm utilizes the array extending capability of fourth-order cumulant and the coprime relationship between the interelement spacings in L-shaped array so that 2D-DOA without ambiguity can be realized under sparse array structure.Compared with two-dimentional virtual-ESPRIT algorithm,the proposed algorithm allows the spacings between the reference elements more than one-half wavelength,which leads to improve direction finding accuracy.Meanwhile,the larger system tolerance is guaranteed by a step-by-step reduction of the number of ambiguities.Computer simulation results verify the effectiveness of the proposed algorithm.