Based on Mie scattering theory, the main process of semi-analytic Monte Carlo simulation is illustrated to research the backscattering properties of aerosol particles to linearly polarized laser in horizontal direction. Four typical environments, five typical aerosol components and three humidity conditions are chosen from optical property libraries of aerosols and clouds. The depolarization ratio, polarization ratio and returned photon number are calculated at 1.5 μm and 2.0 μm, respectively. The variation laws of polarization properties of backscattered laser are acquired with changing of particle sizes of different kinds of aerosol components. Besides, the echoing characteristics of backscattered laser are obtained in four typical aerosol environments. At last, the laser power ratio needed in different environments to achieve the same detection performance is analyzed, which is of reference value to the design and analysis of the coherent lidar systems for the long range and high accuracy observation.