The Monte Carlo method is a good way to calculate the received oceanic lidar signals, but its disadvantage is that the calculation efficiency is very low. The traditional semianalytic Monte Carlo method is improved in this paper, which includes a distorted Henyey-Greenstein function used to approximate the scattering phase function, and the expression of the scattering angle θ obtained from H-G function. The calculations from the received oceanic lidar signals are in good agreement with experiments.