Abstract: In order to solve the problem of DOA (Direction of Arrival) estimation of underwater remote wideband targets,a novel coherent signal-subspace method based on cross spectral matrix of pressure P and particle velocity V using the Acoustic Vector Sensor Array (AVSA) is proposed in this paper.The proposed method is different from existing AVSA based DOA estimation methods using particle velocity information of Acoustic Vector Sensor (AVS) as an independent array element.It is entirely based on combined information processing of pressure and particle velocity,as well as the P-V cross spectrum,has better DOA estimation performance than existing methods in isotropic noise field. By theoretical analysis,both focusing principle of the P-V cross spectral matrix and theory of eigendecomposition based on the P-V cross spectral matrix are given.At the same time,the criterion of source number detection is also presented.Computer simulations with data from lake trials demonstrate,the proposed method is effective and obviously outperforms existing methods in resolution and the accuracy in the case of low Signal-to-Noise Ratio (SNR).