Nanoparticles Aluminum oxide (Al2O3)/ Silicon dioxide (SiO2)photocatalyst was successfully synthesized by urea decomposition & ultrasonic assisted method using metal nitrate as precursors in the presence of sunlight. The as-synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and UV-Vis spectroscopy. The x-ray diffraction pattern indicated that as-synthesized sample had a crystal size for Al2O3with finest particle size of the catalyst (30.096 nmappr.) was obtained at 600°C calcination temperature. Fourier transform infrared spectra confirmed the presence of hydroxyl group and Al-O bond vibration in the catalyst. Experimental result of the Al2O3/ SiO2photocatalyst calcined at 600°C for 2hr, exhibited photocatalytic activity of under sunlight irradiation, the constants of malachite green dye degradation. In the present study, the synthesized nanoparticles used to for the degradation of the dye by direct sunlight exposer.