In this report, SnO2 quantum dots anchored on TiO2 nanospheres (TiO2/SnO2 composites) have been synthesized by a simple one-step hydrothermal process, and then employed as photocatalyst in photodegradation system. The microstructure of TiO2/SnO2 composites reveals that the SnO2 quantum dots are dispersed on the surface of TiO2 nanospheres uniformly. The photocatalytic behavior of the as-prepared samples revealed that the composites exhibited highly efficient performance by degrading 100mL of 10mg/L methylene orange in 15min completely under ultraviolet-visible light. Owning to the special structure of the composites, TiO2/SnO2 shows a more UV–vis light absorption than either pure TiO2 nanospheres or pure SnO2 quantum dots. This study offers a facile method to prepare TiO2/SnO2 composites, which will be a choice for greatly extending potential applications in water pollution treatment, degradation of pollutants and other related fields.