The photocatalytic reduction of CO2 on p-type CaFe2O4 powder has been studied in water. CH3OH and HCHO were produced under illumination. The additions of NaH2PO2 and BaCO3 promoted the CO2 reduction reaction on the CaFe2O4 photocatalyst. It was proven from the dependence of the amount of CH3OH produced on the wavelength of the illuminated light that the electron produced in the conduction band of the CaFe2O4 reduces CO2. The mechanism for the photocatalytic reduction Of CO2 on CaFe2O4 is briefly discussed.