The photoreduction of NO3- and NO2- was performed at 60 degrees C under irradiation of visible light (lambda >400 nm) in the presence of unsupported CdS, H2Ti4O9/CdS and H4Nb6O17/CdS in 10 vol.% aqueous methanol solution. The photoreduction rate of NO3- proceeded in the presence of H4Nb6O17/CdS and H2Ti4O9/CdS nanocomposites although unsupported CdS, H4Nb6O17 and H2Ti4O9 did not show photocatalytic activity for nitrate reduction under visible light irradiation. The photoreduction rate of NO3- and NO2- changed significantly depending on solution pH, i.e., with increasing solution pH the reduction rate of NO3-increased, on the other hand, that of NO2- decreased.