Multi-walled carbon nanotubes (CNTs) with different diameter, different length, and different graphitized degree were grown by chemical catalytic decomposition of hydrocarbons by using different catalysts, different carbon sources under different reaction and pretreatment conditions. The structure and capacitances of these multi- walled CNTs were examined by means of transmission electron microscopy (TEM), auto-sorption instrument and constant current tester. THe experiment results show that the CNTs with 30.0 ～ 40.0 nm in diameter, having shorter length, less graphitized degree, more specific surface area and more pore volume have higher electrochemical capacitance.

Key words: CARBONH, NANOPHASE MATERIALS, CHEMICAL VAPOUR DEPOSITION, ELECTROCHEMISTRY, TEM