The mechanical and electrical properties of Cu-Nb filamentary microcomposite fabricated by the bundling and drawing process were examined. The strength increased gradually with increasing Nb content while the ductility was insensitive to Nb content. The ratios of yield stresses are found to be close to that of Young's moduli in various Cu-Nb microcomposites, suggesting that athermal obstacles primarily control the strength. The fracture morphologies show ductile fractures irrespective of Nb contents. Secondary cracking along the interfaces between subelemental wires was occasionally observed and the frequency of secondary cracking increased with increasing Nb content. The conductivity and the resistivity ratio (rho(295) (K)/rho(75) (K)) decreased with increasing Nb content. The decrease of the conductivity and the resistivity ratio can be explained by the increasing contribution of interface scattering.