When carbon nanotubes(CNTs) are used as negative electrode materials of Lithium ion battery, li+ not only insert in their pipes but also can insert the stitches between pipes, so CNTs can offer a lot of space for li+ encasing. This special microstructure makes the li a little insetting measurement and it is advantage for improving the charge/discharge capacities and current density. Two kinds of CNTs were prepared in this paper, the size and morphology and structure of the CNTs were determined with X-ray diffraction (XRD) and Transmission Electron Microscope (TEM). The charge/discharge characters of CNTs were tested with electrochemical detector and the results showed that there were different between two kinds of CNTs. The CNTs (A) with little d002 had higher initial discharge capacity. At first cycle there was 808.9mAh/g discharge capacity, 214.5mAh/g irreversible capacity and 73.4% discharge efficiency. The CNTs (B) with bigger d002 had initial discharge capacity of 1064.1mAh/g, the first irreversible capacity 627.1mAh/g and 41.1% discharge efficiency. Two kinds of CNTs had better recycle character.