CoO, CuO or NiO supported on Al2O3 photocatalysts were prepared by impregnation and then calcination at 400oC for 3 hours. The obtained samples were physico-chemically studied by Powder X-ray diffraction analysis, X-ray photoelectron spectroscopy and Scanning electron microscopy. The photocatalytic oxidative degradation of aqueous solution of Malachite Green (MG) dye as pollutant using CoO, CuO or NiO supported on Al2O3 under UV irradiation was tested. The results determined that the highest degree of degradation of MG dye after 120 minutes was achieved using NiO/ Al2O3 photocatalyst (82%) than that the other materials CuO/Al2O3 (64%), CoO/Al2O3 (59%) and Al2O3 (50%). The calculated apparent rate constants increasing in the order: Al2O3 (2.7×10-3 min-1)<CoO/Al2O3 (3.9×10-3 min-1)<CuO/Al2O3 (4.1×10-3 min-1)<NiO/Al2O3 (8.4×10-3 min-1).