SiO2 hollow nanostructured fibers with hierarchical walls have been fabricated by the sol-gel combined two-capillary spinneret co-electrospinning technique using triblock copolymer as the porous directing agent. The as-prepared SiO2 hollow nanostructured fibers were as long as 10 cm with the outer diameter of 400-600 nm and shell thickness of 50-200 nm, and their walls contained the random mesopores with the size of 6.6 nm and the micropores with size of 0.6 nm based on the N-2 absorption-desorption isotherm. (C) 2007 Elsevier Inc. All rights reserved.