X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) have been used to investigate oxygen adsorption on the surface of Rb6C60 film at room temperature. The results show that the Rb6C60 surface is sensitive to oxygen adsorption. The absorbed oxygen changes the crystal structure of the film by pulling intercalated Rb atoms to the surface, forming Rb oxides. An initial rapid oxygen uptake is mainly related to the formation of rubidium peroxide (Rb2O2). There exists a strong reaction between C-60 and Rb2O2, leading to the formation of rubidium carbonate (Rb2CO3). At high oxygen exposures, a slow further adsorption of oxygen is associated with the intensity increases of both Rb2CO3 and rubidium superoxide (RbO2) species.