Contact resistance has always been an issue for semiconducting carbon nanotubes (CNT). This paper presents a comparative study on open-ended semiconducting carbon nanotube (4, 0) two-probe systems with metal electrodes of platinum, copper and gold. The local density of states and transmission coefficients has been calculated to explain the electronic structure and transmission properties of two-probe systems. Contact resistance for each two-probe system has been derived from their current-voltage characteristics. Calculations are based on first-principle quantum mechanical density functional, matrix Green's function methods and Landauer-Buttiker formula. Contact resistance is calculated to be highest for the Au electrode while it is least for the Pt electrode. © 2012 Springer Science+Business Media New York.