A mixture of TiO2 and HZSM-5 zeolite was used for photocatalytic degradation of an azo dye, C.I. Reactive Red 2(RR2). The adsorption of RR2 on TiO2 and the effect of TiO2 concentration were studied. HZSM-5 addition was also investigated to ascertain the function of the zeolite on RR2 decoloration. The results show that, the azo dye is quite stable under exposure of UV-C light. Less than 1.7% of the dye was adsorbed on TiO2 surface and 20 min was needed to reach dye adsorption equilibrium. The optimum TiO2 concentration was 320 mg/l. RR2 adsorption rate increased to more than 40% when HZSM-5 addition amount increased to 0.6 g in the solution. The total decoloration rate increased with the addition of HZSM-5 although zeolite addition could not enhance photocatalytic activity of TiO2.