Abstract: Nanoscale CuO powders were prepared by roasting a basic coppper carbonate precursor at 350C for 1 h. The obtained sample's microstructure was determined by XRD and TEM analysis. The results show that the diameter of the nanocrystalline is 30 nm. CuO sol were prepared with dodecylbenzene sulfonate solusion and at pH=3.0 adjusted by HNO₃.