In order to use the large, electro-optic coefficient of a non-linear optical ionic crystal, 4-(p-dimenthylaminostyryl)-1-methylpyridinium tosylate (DAST), a channel optical waveguide structure is needed. We successfully fabricated a waveguide using two methods: by a dry-etching technique and by photo-bleaching. Because DAST has a large optical loss, parts of the waveguide should be composed of a transparent polymer. We used photolithography and a reacive ion etching method to fabricate a serially grafted (conjunct) waveguid of DAST with a transparent polymer waveguide. The waveguide was also fabricated by photobleaching, whereby the refractive indices of the crystal's a- and b-axes were decreased by degrading the crystal. The cladding part of the DAST waveguide was photobleached by irradiating with UV light. The under- and over-cladding layers of these channel waveguides were composed of a UV-cured resin that did not dissolve the DAST crystal. The loss of the crystal waveguide for the crystal b-direction was around 10 dB/cm, due to the scattering loss of the DAST single crystal.