The polyaniline can be synthesized by oxidative polymerization of aniline. The PANI-based nano-composites can be synthesized by the method of polymerization. The oxides of copper are intrinsic p-type semiconductors with relatively small band gaps and show many attractive properties that can be utilized in a diversity of applications This paper includes synthesis of CuO nano-particles, and the polyaniline-CuO nano-composites with five different percentages of CuO nano particles. These samples were characterized by XRD and SEM.