In this study, we focus on the electric optical characteristic of guest/host polymer system. The charge transfer chromophore Wu182 which contain fluorine atom in it was mixed with polymer PMMA and solved in chloroform, while DR1/PMMA served as reference sample. The wu182/PMMA and DR1/PMMA thin films were produced by spin coating. The thin film was poled at the temperature above glass transition temperature until the second harmonic generation signal was present. The poled thin film was placed in one arm of Mach-Zehnder interferometer. Voltage modulation applied to the polymer films can cause phase changes in the interferometer from that we estimate the electro-optic coefficient. From our experiments, we found that modulating frequency had significant influence on the electro-optic effect. The result shows that Wu182 possess large nonlinear optical coefficient. The valid electro-optic coefficient r13 was obtained to be 2.620 pm/V when the frequency was above 6 kHz.