【Abstract】 Background Reactive oxygen species(ROS) play an important role in ischemia-reperfusion(I/R) injury. Accumulating evidence suggests that hydrogen can protect various cells, tissues and organs against oxidative injury by selectively scavenging ROS. Objective To analyse and review the effect and mechanism of hydrogen in treatment of I/R injury, and to get more knowledge about hydrogen and make better clinical applications of hydrogen. Content The mechanism of hydrogen in treating I/R injury was not clear. This paper describes effect and mechanism of hydrogen in treatment of I/R injury and make prospect for research into hydrogen as a therapeutic gas in clinical application. Trend Hydrogen has a wide prospect of clinical application. However, more work is needed to identify the precise mechanism underlying the actions of hydrogen and to validate its therapeutic potential in the clinical setting.