Hydrogen gas has come to the forefront of therapeutic medical gas research. Recent basic and clinical studies have revealed that hydrogen gas is an important physiological regulatory factor, with antioxidant, anti-inflammatory, and antiapoptotic protective effects on cells and organs. Since hydrogen gas is explosive, the methods of hydrogen application become an important issue for researchers. Currently, the methods of hydrogen application are developing rapidly, including inhalation of hydrogen gas, oral hydrogen water, hydrogen saline injection, eye drops, skin smear and bathing, hydrogen gas injection, etc. In this chapter, various methods of hydrogen application are discussed with particular attention to the experimental models and human beings.