In this work, the capped and uncapped copper oxide (CuO) nanoparticles film with an average size ranging from 8.7- 6.2 nm have been prepared by a chemical wet procedure using copper (II) sulfate with sodium hydroxide at 50 °C. The EDTA was used as a capping agent and the obtained samples were investigated by UV visible spectrum. The uncapped and EDTA capped CuO nanoparticles reveals two bands observed at 310 nm and 232 nm for uncapped and EDTA capped CuO nanoparticles respectively. The optical absorption spectra exhibits the energy band gap for uncapped and EDTA capped (CuO) in the range of (3.8 - 4.5) eV respectively.