A novel fast tunable electro-optic (EO) polymer waveguide grating is proposed an d designed. Its resonant wavelength can be linearly tuned by first-order EO effe ct with a high sensitivity of 6.1pm/V. Its spectrum characteristics depend stron gly on many optical parameters of grating, such as refractive index modulation, modulation function, grating period and period number. Material selection, fabri cation technology, EO tunability and polarization dependence of the polymer wave guide grating are also discussed. This waveguide grating not only dispenses with the slow wavelength tuning and large-scale integration inconvenience of convent ional optic fiber gratings, but have many advantages, such as high resonant wave length tuning sensitivity, using same fabrication technology as semiconductor de vices, and polarization independence.