Amorphous carbon nanotubes (ACNTs) showed the different structure with crystal carbon nanotubes, such as single-walled and multi-walled carbon nanotubes due to their unique tube walls. The tube wall of ACNTs is comprised of many single layer graphene sheets which present long-distance disorder and short-distance order. Herein, we mainly studied the electrochemical property of ACNTs as anode materials for lithium ion secondary batteries and the mechanism of intercalation lithium. The electrochemical performances of as-grown and oxidized ACNTs were tested by two-electrode cell. The results indicate that the reversible capacity of ACNTs oxidized at 300 degrees C reaches 530 mAh/g and after the first 5 cycles the capacity remains 93%. The intercalation Li of ACNT include the inner wall and the side wall between graphene sheets. ACNTs offer a new exciting alternative to the traditional materials used for fabrication of lithium ion secondary batteries.