The thermoelectric transport properties of Bi/Sn and Bi/Sb core/shell (C/S) nanowires grown by the method of on-film formation of nanowires were systematically investigated. The electrical conductivity and Seebeck coefficient of nanowires with different diameters were measured as a function of the temperature. The contribution of Sn and Sb shells to the total transport in the C/S nanowires was determined using analytical fitting based on the parallel combination of the conducive system model. The carrier-interface boundary scattering at the C/S interface was quantitatively evaluated as the sheet resistance. In addition, the effect of hole doping on the transport properties was also observed in the Bi/Sn C/S nanowires.