Carbon nanotubes (CNTs)/carbon microelectromechanical systems (C-MEMS) composites were fabricated as electrode materials for on-chip supercapacitors. By using photolithography and pyrolysis process, 3-D C-MEMS architectures were prepared. The iron catalyst particles were conformally coated on the C-MEMS by electrostatic spray deposition (ESD) and CNTs were synthesized on the surfaces of C-MEMS by catalytic CVD method. The CNT/C-MEMS composites exhibited higher specific capacitance than C-MEMS. Furthermore, the composites with more homogeneous CNTs showed better capacitance. After treatment of oxygen plasma, the specific capacitance of the composite increased due to the contribution of oxygen functional groups.