The present work is focused on the homogeneous and heterogeneous photocatalytic degradation of dye Acid Orange 8(AO8), a non biodegradable dye from dye manufacturing industries. Aqueous solutions of azo dye Acid Orange 8 were treated with Fenton reagent and titanium Dioxide. The degradation of dye was determined by visible spectrophotometer .Results indicate that dye degradation is dependent on concentration of dye ,photocatalysts (Fenton reagent and titanium Dioxide) ,Hydrogen peroxide(H2O2) and ph of the experimental solutions . The kinetics of degradation of the dye in the dilute aqueous solutions follows first order kinetics. The results indicated that the treatment of the dye by Fenton reagent was more efficient than Titanium dioxide at optimum conditions.