A novel channel waveguided TE/TM mode splitter is presented. This splitter can spatially separate the TE and TM mode components and is compatible with single mode fiber systems. The operation principle is as follows. Two straight waveguides are formed closely parallel to each other on c-plate LiNbO3 by preferential Ti diffusion. An Al strip loaded on waveguide 2 induces a large change in the propagation constant for the TM mode, so that the TM mode component, fed into waveguide 1, cannot couple to waveguide 2 (“straight-through state”). By applying external voltages V1 and V2 to the two planar electrodes, formed on waveguide 1 with an Al2O3 buffer layer in-between, a complete power transfer from waveguide 1 to waveguide 2 takes place for the TE mode (“crossover state”). Less than -20 dB crosstalk was realized at 1.15 µm wavelength for V1=20 V and V2=-15 V. The insertion loss was 1.7 dB.