The improvement of photocatalytic activity of TiO2 has been explored. TiO2 has been doped with some transition metal elements for new photocatalytic materials. They were prepared using nitrates of Fe, Cu and Zn. Their photocatalytic activities were investigated by conducting a semi-batch experiment. The degradation of aqueous humic acid was performed under near-visible irradiation. For examining the photocatalytic characteristics of the new materials, the dissolved organic carbon and the UV254 absorption of humic acid were analyzed. The new metal-doped photocatalysts showed higher photoactivities than the synthesized pure TiO2. And photodegradation result of humic acid by the new metal-doped material was even better than by the commercial Degussa P-25 TiO2 at wavelengths of 315 nm - 400 nm.