Atmospheric aerosols are mixtures of solid or liquid particles which are suspended in the atmosphere. Atmospheric aerosols reside mainly in the two lowest layers of the atmosphere: the troposphere and the stratosphere.The earth's radiation budget is the balance between incoming energy from the sun and outgoing energy from the earth. When the shortwave emitted from sun is reaches to the earth atmosphere, about one third of the shortwave radiation is re ected back to space by clouds, aerosols, atmospheric molecules and the surface. The radiative properties of atmospheric aerosols are critically dependent on their refractive indices as a function of wavelength and also on their size. Theoretical modelling of light scattering by spherically assumed aerosol particles is always desired not only to gain insight to radiative transfer process but also to supplement ground based experiments. In the present study, we attempt to compute scattering phase matrix elements of P11, P12, P33 and P34. Scattering phase matrix elements of P11, P12, P33 and P34 are known as phase function. The phase function represents the angular distribution of the scattered energy.