A Monte Carlo algorithm is presented to model characteristics of polarized laser in thick fog and thin fog media. When the wavelengths of polarized laser are equal,the depolarization characteristics of the polarized laser are analyzed separately in the different fog particle radii. And the changes of polarizing angle are compared in the different transmitting range. The simulation result shows that,1) when the granule radius is small,the biggest changes of backward polarization angle are mainly centralized,and the changes of all forward polarization angles are very small. The forward scattering polarization angle of a single sphere granule is invariable; 2) more and more complex side lobes of polarization angles appear with the increase of the fog particle radius; 3) the diffused light polarization angles increase with the increase of optical transmission distances,and the depolarization angles of laser in thick fog are bigger than those in thin fog.