Silica nanotubes are widely used in nanotechnology because of their unique properties. In this paper, silica nanotube fibers with all thickness less than 100nm and uoter diameters ranging between 300nm and 500nm are fabricated using the centrifugal jet spinning (CJS) technique with tow steps: spinning and annealing. Polyvinylpyrrolidone-silica (PVP-silica) composite fibers are initially spun with engineerd spinning solutions. By controlling the degree of tetraethyl orthosilicate (TEOS) hydrolysis, unreacted excess TEOS is introduced into spinning solutions to form a dual-solvent system with ethanol. Because of the differential vapor pressures of TEOS and ethanol as well as their differential solubility of PVP and dispersion of silica, dual-solvent evaporation induces phase separation in the spinning. Silica nanotube fibers are obtained with subsequent thermal annealing of PVP-silica composite fibers. The diameter and wall thickness of the siilca nanotubes can be controlled by tuning the content of TEOS in the initial spinning solutions. The mechanism of tubular structure formation is also explained and examined with the help of elemetal analysis. The method used in this paper can provide a new direction for efficient and large-scale fabrication of nanomaterials with controlled morphologies. (C) 2014 Elsevier B.V. All rights reserved.