The reflectivity, polarization degree, intensity contrast and polarization contrast of s light and p light which scattered from aluminous plane and concrete floor, were theoretically calculated based on the specular reflected model at visible and near infrared under natural illumination condition. The results of calculation and analysis indicated that the polarization characteristics of object were determined by the difference of reflected capabilities of s light and p light. Then the difference was influenced by incident angle, wavelength, the surface roughness of object and the refractive index of the material. And the intensity contrast and polarization contrast were influenced by them firsthand. Consequently, the research of surface characteristics of object and background are of great significance for object detection and recognition in the mix natural background.