The concentration of TiO2 and the composites of TiO2 and 5A zeolite were studied in order to improve the photocatalytic activity of TiO2. Methyl orange aqueous solution was taken as imitated polluted water. The results indicated that the optimum dosage of TiO2 was 200 mg/l. A simple mixture was prepared by adding TiO2 and 5A zeolite together into methyl orange solution. The optimum TiO2:5A ratio was 1:11. Composite of zeolite 5A and TiO2 was also prepared using solid-state dispersion method. Photocatalytic activities of the composite after each preparation step were evaluated. Although the results showed that their photocatalytic activities decreased to some extent compared with pure TiO2, the composite could be easily separated from the treated solution.