In this paper, to improve the usage of visible light in titanium dioxide nanorod arrays (TNR), MoS2/TiO2 heterostructure arrays modified with Ag nanoparticles are successfully synthesized by hydrothermal and photodeposition methods. The morphology, microstructure, photoelectrochemical and photocatalytic properties of samples are discussed. The experimental results show that Ag/MoS2/TNR can effectively extend the absorption edge of visible light, retard the charge recombination and reduce the interface resistance, which greatly enhances the performance of photoelectrochemistry and photocatalysis. When the hydrothermal reaction time is 12 h, the sample exhibits the best transient photocurrent (120 mu A/cm(2)) and photodegradation efficiency (75%); the values are 12 and 5 times than those of bare TNR, respectively. Based on the above results, the synergistic effect of MoS2/TiO2 heterostructure, surface plasmon resonance of Ag nanoparticles and narrow bandgap of MoS2 is proposed to explain the enhancement of these properties.