The purpose of this paper is to develop a rational engineering conductive carbon filled composite through understanding of the effect of conductive carbon black. Polycabonate(PC), Acrylonitrile Butadiene Styrene copolymer(ABS) and PC/ABS resin were used as matrix of the conductive polymer composites. From the experimental results, PC filled with the fiber shaped carbon black showed a possibility to be a rational engineering conductive composite.