A jet electrodeposition device was carried out to prepare Cu-Al2O3 nanocomposite coatings. The influence of the concentration of Al2O3 in the electrolyte and the parameters on the content of the Al2O3 in the deposit was investigated. The coatings ingredient and microstructure was measured by the scanning electron microscope, the microhardness tests were conducted on an microhardness tester. The results show that the copper deposited layers have nanocrystalline microstructure with grain size of about 50nm . The amount of Al2O3 in composites first increased and then decreased with an increase in the concentration of Al2O3, current density, temperature and jet velocity. The composite with optimum atomic percent of Al2O3 (14.4 at%) can be obtained at the concentration of 30 g/l , cathodic current densities 300 A/dm2, temperature 30°C, and jet velocity 8 m/s . The addition of Al2O3 in copper increases the microhardness of the electrodeposited coatings.