In a new organic polymer photorefractive material, the two beam coupling experiment demenstrates that the gain coefficients of two beam coupling exceed the absorption coefficient. The measured maxium diffraction efficiency is high to 86% in a 105 μm thick polymer film. The grating growth response time is in the order of 100 ms. The material also exhibits a net gain of two beam coupling over 200 cm -1. A new way to analysis the photorefractive mechanism is suggested.