Prominently enhanced capacitive performance of well-dispersed RuO2 nanoparticles (NPs) on nitrogen-containing carbon nanotubes directly grown on Si has been achieved. The function of nitrogen amalgamation is to create preferential sites on carbon nanotubes (CNTs) with lower interfacial energy for attachment of RuO2 NPs. This crucial phenomenon leads to a significant improvement of the overall specific capacitance up to the measured scan rate of 2000 mV/s. This work demonstrates that superior electrochemical performances for supercapacitor applications can be achieved with RuO2-CNT-based electrodes using nitrogen-incorporation technique. (c) 2007 The Electrochemical Society.