Conducting polymers of alkylanilines, pyrrole, and their conducting composites were synthesized by oxidation polymerization. The oxidants used were KIO 3 and FeCl 3 for the polyalkylanilines and polypyrrole (PPy), respectively. Among the polyalkylanilines synthesized with KIO 3 salt, the highest conductivity was obtained with poly(2-ethylaniline) (P2EAn) with a value of 4.10 ϫ 10 Ϫ5 S/cm. The highest yield was obtained with poly(N-methylaniline) with a value of 87%. We prepared the conducting composites (PPy/P2EAn and P2EAn/PPy) by changing synthesis order of P2EAn and PPy. The electrically conducting polymers were characterized by IR spectroscopy, ultraviolet-visible spectroscopy, thermogravimetric analysis, and Xray diffraction spectroscopy. From the results, we determined that the properties of the composites were dependent on the synthesis order of the polymers. The thermal degradation temperature of PPy was observed to be higher than that of the other polymers and composites. We determined from X-ray results that the structures of the homopolymers and composites had amorphous regions (88 -95%) and crystal regions (5-12%). From the Gouy balance magnetic measurements, we found that the polymers and composites were bipolaron conducting mechanisms.