The structural and electrical properties of polyaniline-cobalt sulphate nanocomposite prepared by chemical method.Polyaniline-cobalt sulphate nanocomposites were synthesized by the cobalt sulphate and ammonium persulphate and aniline.This paper reports on chemical technique using for synthesis of cobalt nanoparticles in the composite bridge is aniline. Electrical conductivity of polyaniline with cobalt sulphatena noparticles measured. Increasing amounts of cobalt nanoparticles in the sample equivalent to the highest electrical conductivity. We also studied morphology of polyaniline-cobalt sulphate nanocomposite. Size of cobalt nanoparticles, is ~ 65-75 nm.