The powders of ilmenite structure NiTiO3 were prepared by a modified Pechini process using tetrabutyl titanate and nickel acetate as raw materials, and using citric acid and ethanol as a chelating agent and a solvent respectively. The powder samples were characterized by thermogravimetric and differential thermal analysis (TG-DTA) and X-ray diffraction (XRD). The photocatalytic activity of NiTiO3 under the irradiation of ultraviolet rays (UV) light was evaluated by degrading humic acid (HA) in water as a probe reaction. The possible photodegra-dation mechanism was studied by the examination of active species -OH, , and holes (h+) through adding scavengers. The TG-DTA and XRD results indicated that the good crystal structure of ilmenite phase NiTiO3 could be obtained when the Ni-Ti citrate complex was cal-cined at 600°C. The photocatalytic activity experiments indicated that NiTiO3 had favourable photocatalytic activity under the irradiation of UV light, and the photocatalytic degradation rate of HA reached 95.3% after a 2.5 h reaction with the photocatalyst calcined at 600°C and a photocatalyst dosage of 0.4 g/L. The possible photocatalytic mechanism was deduced that holes (h+) and-OH radicals are the major reactive active species in the photocatalytic reaction, and dissolved oxygen plays a weak role in the degradation of HA. The powders of ilmenite structure NiTiO3 were prepared by a modified Pechini process using tetrabutyl titanate and nickel acetate as raw materials, and using citric acid and ethanol as a chelating agent and a solvent respectively. The powder samples were characterized by thermogravimetric and differential thermal analysis ( TG-DTA) and X-ray diffraction (XRD). The photocatalytic activity of NiTiO3 under the irradiation of ultraviolet rays (UV) light was evaluated by degrading humic acid (HA) in water as a probe reaction. The possible photodegradation mechanism was studied by the examination of active species -OH, and holes (h +) through adding scavengers. The TG-DTA and XRD results indicated that the good crystal structure of ilmenite phase NiTiO3 could been obtained when the Ni-Ti citrate complex was cal -cined at 600 ° C. The photocatalytic activity experiments indicating that NiTiO3 had favorable photocatalytic activity under the irradiation of UV light, and the photocatalytic degradat ion rate of HA reached 95.3% after a 2.5 h reaction with the photocatalyst calcined at 600 ° C and a photocatalyst dosage of 0.4 g / L. The possible photocatalytic mechanism was deduced that holes (h +) and-OH radicals are the major reactive species in the photocatalytic reaction, and dissolved oxygen plays a weak role in the degradation of HA.