Abstract: This paper studies the preparation of TiO₂.Al₂O₃ composite photocatalyst attached to the hollow glass microbeads surface by Sol-gel technique using titanium tetraisopropoxide ［Ti(iso-OC₃H₇)4］ and triisopropyl organophosphorous as material. The photocatalytic degradation of organophosphorous pesticide is studied, while comparing the photoactivity of TiO₂.Al₂O₃/beads with the photoactivity of Degussa P-25 TiO₂. The results show that the best composite photocatalyst produces 1.4 times of photoactivity of P-25 TiO₂, and the mole ratios of TiO₂.Al₂O₃ have the best value. Moreover, the adsorption of TiO₂.Al₂O₃/ beads is studied, and the composite photocatalysts are characterized by XRD and TEM.