Nanostructured CuO powders have been synthesized using chemical methods in the current study. Ammonium oxalate and copper nitrate were used as the precursor materials. The weight ratios of the raw materials (ammonium oxalate/copper nitrate) were 1.1, 1.2, 1.3, and 1.4. As a result of chemical reaction (between them), copper oxalate was synthesized. Produced samples were analyzed by XRD and SEM. The results show that the best ratio (for ammonium oxalate/copper nitrate) is 1.2. Produced copper oxalate powder was heated at 600, 700 and 800oC. The final product was CuO nanopowder. XRD studies indicate that the highest ratio of Cu2O to CuO was observed in the specimen heated at 700oC.