We have reported that TiO2 particles prepared in reverse micelles showed high photocatalytic activity in an amorphous rather than anatase state and that the amorphous state changes easily into the anatase state just by irradiating visible light. So we prepared Au/TiO2 complex particles which included An colloids in TiO2 by the reverse micelle method. We found that Au colloids exhibited the sustaining effect of amorphous TiO2 particles. Moreover, Au/TiO2 complex particles showed higher photocatalytic activity than single TiO2 particles and also could be used repeatedly.