The carbon nanotubes according to the present invention can provide higher conductivity by allowing the BET and crystal size to satisfy the conditions expressed by formula 1 below, and consequently, can improve the conductivity of a carbon composite material containing the carbon nanotubes. Lc×[Specific surface area of CNT (cm2/g)]1/2>80  [Formula 1] wherein, Lc is crystal size measured by X-ray diffraction.