Gallium borate nanowires have been synthesized using a simple and readily scaleable solid-state reaction among boron, boron oxide and gallium oxide. The GaBO3 nanowires have diameters ranging from 90 to 150 nm and lengths of several hundreds nanometer, exhibiting a poor crystallization. After a nanoscale support catalyst Fe2O3/Al2O3 was used as additive in the reaction, the diameters, lengths and crystallization were effectively improved. The nanowires exhibit a well-crystallized one-dimensional single-crystal structure with diameters ranging from 20 to 60 nm and lengths up to several micrometers. The growth mechanism was also presented in this letter. (C) 2003 Elsevier B.V. All rights reserved.