A method of optical proximity correction, suitably applied to a photolithography process with a high numeric aperture. The exposure light comprises a P-polarized light and an S-polarized light perpendicular to the P-polarized light. The P-polarized light has a transmission coefficient larger than that of the S-polarized light. In this method, different optical proximity correction modes are applied to the patterns with different orientations. While correcting any pattern, the ratio of transmission coefficient of the P-polarized light to the S-polarized light and the polarization angle between the pattern orientation and the polarization direction of the P-polarization/S-polarization light are considered.