Y-Titanylphthalocyanine (Y-TiOPc) is widely used as the photoconductor for laser printers. However, little is known about its crystal structure. An attempt has therefore been made to grow single crystals from water containing solution on the assumption that the Y-phase includes water. An autoclave was utilized for the crystal growth so as to suppress the solvent evaporation and thus to increase the solubility of TiOPc. The single crystals have successfully been obtained, but these are found to be phase I according to the structure analysis. However, our single crystal exhibits an intense, Y-phase-like reflection around 790 nm as revealed from polarized reflection measurements on single crystals. The present fact evidently indicates that the Y-like layer of TiOPc is formed on the surface (thickness at least 2500 Å) and that the core of the single crystal is phase I. The present interpretation is also borne out by X-ray diffraction analysis on powders as well as XPS measurements monitoring O1s and Ti2p signals.