Thermochromism was found in phase II and Y-form oxotitanium phthalocyanines (TiOPcs) from the observed temperature dependence of the absorption and X-ray diffraction spectra of various crystal forms of TiOPcs. Thermochromism has not been observed in amorphous and phase I TiOPcs. The temperature dependence of the electroabsorption spectra of phase II was also different from that of phase I. This distinctive behavior was discussed in terms of the crystalline packing structure of each TiOPc.