Silver-TiO2 nanofibers (Ag/Ti = 1/50) were fabricated by the electrospinning method, followed by heat treatment at 200 degrees C and calcination at 550 degrees C. The electrospinning solution was comprised of AgNO3 and titanium tetraisopropoxide (TTIP) with polyvinylpyrrolidone (PVP). Alternating irradiation of the silverTiO(2) nanofibers with ultraviolet and visible light can interconvert the silver species on the TiO2-based nanofibers to yield Ag metal and Ag2O, respectively, and this process has been characterized by UV-visible spectra, TEM, XRD, and XPS. The interconversion process can be rationalized in terms of the photoreduction of Ag2O by TiO2 and the oxidization of Ag by visible light. Acetaldehyde photodecomposition measurements indicate that Ag2O has better mineralization ability than Ag-0 in this kind of silver-TiO2 nanofiber photocatalytic system. The photoinduced conversion of composition on TiO2-based nanofibers may find applications in photocatalysis, antibacterial technology, and other areas.