Vanadyl-phthalaocyanine (VOPc) films were prepared on KCI substrate by a molecular beam epitaxy (MBE) method. The SEM image revealed that a VOPc single crystal of 120)mumX120)mum grew on the KCI substrate after annealiing for 360 minutes. Its average film thickness was about 110 nm. The growth of single crystal was assisted by the surface diffusion of VOPc molecules and the difference in chemical potential between single crystals. Therefore, the single crystal grows merging neighboring grains and/or VOPc molecules surrounding. The VIS/UV spectrum of single crystal had the absorption peaks at 700nm and 860nm and also the absorption shoulder at 640nm. The maximum absorption peak is at 860nm. According to Griffiths et al., the phase having peaks at 680nm and 740nm is called Phase I and the phases having a main absorption peaks at 820nm and 830nm are called Phase II and Phase III, respectively. Phases having a main absorption peaks at 780nm and 810nm are called Pseudomorphic layer and epitaxial growth, respectively. As mentioned above, the phase having a main absorption peak at 860nm has not been reported so far. We call it Phase IV. The VOPc film having Phase IV shows a third harmonic (TH) generation. The TH susceptibility is larger by about 103 times than that of quartz glass. This indicates that Phase IV has high molecular packing density and good nonlinear optical properties. Therefore the single crystal on KCI substrate prepared by MBE is expected to apply to optical switching, modulation and memory (RAM and ROM).