Abstract: Aiming at the influence of velocity profiles on the spatial correlation of low-frequency sound field in shallow water, the variation of spatial correlation under different velocity gradients and different array element intervals is simulated and analyzed by using the RAM program, which is based on the parabolic equation. Simulation results show that with the increase of positive velocity gradient, the vertical correlation coefficient decays more slowly and the horizontal-longitudinal correlation coefficient decays faster, both the vertical and the horizontal-longitudinal correlation lengths fluctuate violently; with the increase of the negative velocity gradient, the vertical correlation coefficient decays faster and the horizontal-longitudinal correlation coefficient decays more slowly, the correlation length of both types fluctuates slowly.