Through the analysis of electric polarization angle difference between surface and bulk scattering by first-order perturbation angle-resolved scattering theory, the electric polarization angle between surface and bulk scattering is constant when incidence angle and scattering angle are decided. So polarization angle of polarizer and analyzer are controlled to eliminate surface scattering or bulk scattering, and the bulk scattering or surface scattering can be detertal independently. A method in theoritical is applied to eliminating surface or bulk scattering of transparent substrate in this paper, when scattering plane in the incident plane and polarizer angle is 45°, through the numerical study, the analyzer angle is gotten in s-p plane. Thus, the surface scattering or bulk scattering is obtained to study surface roughness or bulk inhomogeneous.