Carbon nanotube as conductive filler was added into poly(lactic acid) matrix through the ball milling and mixing method respectively, and the antistatic properties of poly (lactic acid)/carbon nanotubes composite were studied. The structure, glass transition temperature, crystallinity and melting point of poly(lactic acid) filled with functional carbon nanotubes were analyzed by FT-IR and DSC. The results show that the integral structure of poly(lactic acid) does not change, glass transition temperature and melting point decrease a little. The impact resistance and conductive properties of composites tested by impact resistance experiments and conducting performance tests respectively are improved with the contents of carbon nanotubes increasing. Ball milling process could make carbon nanotubes form conductive path more easily than mixing process. The mechanical properties of polylactic acid are improved after adding functional carbon nanotube.