Precise and uniform metallization of double-stranded DNA by the selective electroless plating method was investigated for the fabrication of nanowires. Cis-platin was bound to template DNA molecules and reduced to platinum which then catalyzed silver metal deposition. The DNA molecules combined with the platinum clusters were stretched and immobilized on a glass substrate using the Langmuir-Blodgett (LB) method. The electroless plating of the platinum-bound DNA molecules by the reduction of silver ions yielded uniform silver nanowires (ca. 50nm in width and height) along the stretched DNA molecules. Conductive AFM measurements revealed that a high electric conductivity over a length of 6mum from the edge of a micro electrode.