ZnO nanofibers doped with different Al concentration were fabricated by electrospinning method. The nanofibers annealed at 600 degrees C showed a polycrystalline hexagonal structure with the diameter of about 150 nm. The grain size of the nanofibers decreased after Al doping. The photoluminescence spectra of all the samples presented two luminescence bands at green and orange ranges. And both bands decreased simultaneously with the Al concentration increasing. The luminescence centers of the green and orange bands could be attributed to oxygen vacancies and excess oxygen, which might reside inside the polycrystalline grains and near the grain boundaries, respectively. And the simultaneous decrease of both luminescence bands in the Al-doped ZnO nanofibers might be due to the inwards penetration of excess oxygen. (C) 2010 Elsevier B.V. All rights reserved.