Abstract: Polypyrrole/ carbon black conducting composites were prepared by chemical polymerization adsorbedpolypyrrole onto conducting carbon black. The constitution, st ructure and performances of the composites werestudied and characterized by FT-IR, TGA, SEM, four-probe and elect rochemical test measurement s. The int roduction of conducting carbon black not only increases the conductivity f rom 6.52 S/ cm to 13.42 S/ cm but also improvesthe bulk density, particle morphology and the film molding property of the composites. Consequently the performances of Li/ PPy secondary battery are enhanced when the composites are employed as positive elect rode materials. Itwas found that the initial specific discharge capacity of the battery reaches 41 mAh/ g calculated by PPy, and the discharge capacity shows a slight decrease and the coulombic efficiency is still over 98 % af ter 30 charge-discharge cyclesat room temperature.