Multi-walled carbon nanotubes (MWCNTs) with different diameter range are employed as the anode materials in lithium-ion batteries (LIBs). The influence of diameter and pore structure on the electrochemical behavior of MWCNTs has been investigated by characterization of morphology and structure, nitrogen adsorption and desorption measurement, charge/discharge tests, and electrochemical impedance spectroscopy (EIS). The results show that MWCNTs with a diameter of 40-60 nm display the highest specific capacity (187.4 mAh g(-1) at the charge/discharge rate of 50 mA g(-1)) and good cyclability (101.9% Coulomb efficiency after 50 cycles). The excellent electrochemical performance verifies the feasibility of MWCNTs as a promising candidate for the anode of LIBs. (C) 2012 Elsevier B.V. All rights reserved.