Abstract: The effects of reflective index and particle size parameters on optical properties of atmosphere aerosol particles were studied by using Mie scattring method at the wavelength of 0.65 m over small scales. The influence of the imaginary part of refractive index on the aerosol particle scattering phase function was analyzed. The results show that, in the small scale, the light scattering properties are sensitive to the refractive index and size parameter. The influence of the real part of refractive index and size parameter on non-scattering angle optical parameters is a degree of symmetry. It was also found that in the special position of the scattering angle, no matter the single particle or polydisperse particles, the scattering phase function are independent of the imaginary part of refractive index, scattering phase functions of different imaginary part of refractive index have an intersection point in the forward direction, the intersection point takes Gaussian distribution with the increase of particle size parameter. With the increase of particle size parameter, the intersection point would move to the small forward direction, and gradually become discrete. This work is of reference value in studying the scattering properties of aerosols and their climatic effects.