Polarization Properties of One-dimensional Ternary Photonic Crystal are studied by using characteristic matrix method,the results showed that,in first-order forbidden band,there was omni-directional photonic band gap in photonic crystal with the incidence of S-polarization,that the forbidden band width decreased with the increase of incidence angle of P-polarization and omni-directional photonic band gap was formed only in the range of short-wave in the forbidden band,however,...