The electronic states of Li2O were observed using ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS). By exposing to the different pressures of H2O vapor, the peak attributed to the surface hydroxyl groups was observed. After exposing to the enough pressure to compose LiOH, an obvious change has not been observed in UPS spectra by the precision of the present study although the change was observed in XPS. The density of states (DOS) of Li2O was calculated using CASTEP code, and the obtained spectra were discussed using the results of the calculation.