Bi porous films were prepared via a simple process which involves solvothermal or thermal treatment of Bi(NO3)3 and alumina membranes. The reducing reagent is helpful for the growth of Bi in the channels of alumina templates. However, Bi networked X-shape nanowires would form when the reaction was carried out under vacuum system. This method has been successfully applied to the synthesis of other porous metal film. The pressure, reducing reagent and starting materials play a key role in the growth of Bi films. A possible formation mechanism of Bi films and nanowires is proposed.