Abstract: The polarization characteristic of Newton telescope is analyzed with the common-path heterodyne interferometry. The reflectance formulas of both s-polarized light and p-polarized light incident on each point of the telescope were derived based on the Fresnel law. The schematic diagram of the experimental setup for measuring phase difference and analyzing the polarization characteristics of Newton telescope with the common-path heterodyne interferometry is given. The influences of Newton telescope on s-polarized light and p-polarized light reflectance, phase difference and incident light polarization degree are analyzed with 632.8nm heterodyne laser source. The curves corresponding to reflectance, phase difference and polarization degree at different incident angles were drawn. The results show that the Newton telescope coated with aluminum produces little influence on the polarization characteristic of incident light, the reflectance difference between s-polarized and p-polarized lights is less than 0.01, and the variation range of the polarization degree is less than 0.07. Therefore, it is suitable for the receiving subsystem of the laser remote polarization imaging system.