This study investigated the coaxial electrospinning process of silver filling in TiO2 ultrafine hollow fibers using Polyvinyl pyrrolidone (PVP) sol/titanium n-butyloxide (Ti(OC4H9)(4)) and PVP sol/silver nanoparticles as pore-directing, agents. The bicomponent fibers were heat treated at 200 degrees C and calcined at 600 degrees C. Silver particles having diameters of 5 to 40 run were deposited on the inner surface of the long hollow TiO2 nanofibers (outer diameter of 150-300 nm) with mesoporous walls (thickness of 10-20 nm). The morphological structure of the filled ultrafine hollow fibers has been studied by means of infrared (IR) spectrum, X-ray diffraction (XRD). scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The diameters and wall thicknesses of the hollow fibers could be tuned by adjusting the electrospinning parameters. Compared with other nanostructured TiO2 materials, such as mesoporous Ag-TiO2 blending fibers, TiO2 hollow nanofibers, TiO2 nanofibers, and TiO2 powders, the silver filled TiO2 hollow fibers exhibited a higher photocatalytic activity toward the degradation of methylene blue.