© 2018, National Institute of Optoelectronics. All rights reserved.CuO-PVA nanocomposite films were prepared successfully by sol-gel method with Cu(CH3COO)2.H2O as a precursor and Poly vinyl alcohol(PVA) in aqueous solution. The effect of annealing conditions such as annealing temperature and rate of annealing temperature, immersion cycle, and dip coating speed on the optical, film thickness, and particle size of CuO nanocomposite films has been studied by field emission scanning electron microscopy (FE-SEM), and UV-Visible spectroscopy techniques. According to the FE-SEM results, the sizes of the CuO nanostructures are below 20nm for annealing temperature of about 350 and 500°C. By analyzing the results obtained from the UV-Visible spectrum of the as-prepared CuO nanocomposites a blue shift in band gap energy observed. The blue shift is due to the quantum confined charge carriers in very small nanometer-sized space.