A TE polarizer on the KTP substrates is reported. Planar and channel waveguides fabricated by an ion exchange process were studied. An anomalous change was found in the process of ion exchange. An approximate relation was introduced to study propagation properties of different wavelengths. Optical field distributions in channel waveguides were measured and a distribution formula was proposed which fit the measurement distribution very well. Finally a TE waveguide polarizer was fabricated.