Fe-doped anatase TiO₂ (A-TiO₂)photocatalyst was prepared through a hydrothermal procedure by using FeCl₃·6H₂O as the iron source. With bromocresol green taken as degradation target, the bromocresol greens initial concentration, TiO₂ dosage, amount of iron-doped were investigated for their effects on kinetic equation of catalytic degradation reaction by visible light of self made catalyst. The results showed that the degradation rate 76. 05% of bromocresol green was the maximum figure under the following optimal conditions: bromocresol greens initial concentration ρ0 10 mg/L(pH=7), catalyst dosage m 0. 6 g/L, amount of iron-doped 4 %(molar fraction), and irradiated by 40 W filament lamp for t=3 h at room temperature. The photocatalytic degradation curve of bromocresol green conformed to the first-order reaction kinetic equation. Under the above optimum conditions, the observed reaction rate constant K achieved the maximum value of 0. 389 7 h^-1.