NaTaO3:La photocatalysts were prepared under air, O-2 and H-2/Ar atmospheres by solid-state reaction method. The photocatalytic activities of these samples were evaluated from the photocatalytic hydrogen evolution from the methanol solution and pure water, and decomposition of Rhodamine B (RhB). NaTaO3:La prepared under air atmosphere showed the best photocatalytic performance in all the evaluation of photocatalytic activity. The sample prepared under H-2/Ar atmosphere showed higher activity in pure water splitting than that under O-2 atmosphere, which was opposite in H-2 evolution reaction and photocatalytic degradation of RhB. (C) 2014 Elsevier B.V. All rights reserved.