Uniform one-dimensional V2O5@polyaniline core/shell nanobelts have been fabricated by a simple in-situ polymerization method in the absence of any surfactant and additional initiator. The influences of pH and additional initiator on the morphology of the resulting products are investigated. The pH value is important for the formation of V2O5@polyaniline core/shell nanobelts, which preserve the original morphology of V2O5 nanobelts. With a decrease in the pH value to 0 the original morphology of the V2O5 nanobelts is destroyed. When ammonium peroxydisulfate is used, some separated polyaniline nanofibers are formed. The formation of the V2O5@polyaniline core/shell nanobelts can be related to the in-situ polymerization of aniline monomer by etching V2O5 nanobelts. The electrochemical lithium intercalation/deintercalation of V2O5@ polyaniline core/shell nanobelts is investigated by cyclic voltammograms.