Abstract: Polytrifluorostyrene(PTFS) was prepared by emulsion polymerization, and then a series of nitro polytrifluorostyrenes (PTFS-NO2) with different nitrification rates were prepared, using the mixture of nitric acid and sulfuric acid as nitrating agents. The resultant polymers were characterized by FT-IR, NMR,DSC, TG etc. The optical properties of PTFS-NO2 thin films were also studied. Results show that the nitrification rates of the polymers can be adjusted by changing the ratio of mixed acids and reaction temperature. Comparing with PTFS, the PTFS-NO2 has a significant increase in both optical birefringence and light transmission. The birefringence of PTFS-NO2 can be as high as 0.018 7.