Photocatalyst Bi1-xSmxVO4 were prepared by solid phase reaction and characterized by XRD, UV-visible DRS, BET, and SEM. Bi1-xSmxVO4 showed two structures with the component content. When the composition was above x = 0.3, Bi1-xSmxVO4 were of single phase with tetragonal type and can be regarded as solid solutions of was BiVO4 and SmVO4. When Bi1-xSmxVO4 was loaded with 0.3 wt% Pt, the samples showed photocatalytic activities for water decomposition to hydrogen under UV light. Among these catalysts, Bi0.5Sm0.5VO4 showed the best photocatalytic activity for water splitting, which indicated synergistic of Bi/Sm enhanced the photocatalysis efficiency. What's more, Bi0.5Sm0.5VO4 loaded with other co-catalysts was found to act as a photocatalyst for water decomposition to hydrogen and oxygen under UV light irradiation, and the photocatalyst loaded with Pt/Cr2O3 had the best photocatalytic property. The amounts of the produced hydrogen and oxygen, respectively, were about 188.25 mu mol h(-1) g(-1) and 95.90 mu mol h(-1) g(-1). This study indicated that the formation of solid solution was the feasible method to adjust energy band and synergistic of Bi/Sm can enhance the photocatalytic activities of water decomposition. Copyright (c) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.