In near field optical storage system of solid immersion lens, the polarization of the incident light affects the near field optical image greatly. In this paper 3 component optical fields intensity of focused linear polarized Gauss beam in the focal plane and the intensity patterns in the sections of various distance from the focal plane are simulated using 3 dimensional finite difference time domain (FDTD) method. The results show that the image pattern in the focal plane or the sections near the focal takes on approximate ellipse, while the patterns in the planes of far region displays asymmetrical round.