Abstract： The unique molecular structure of hydrogen allows it to easily diffuse into the cytoplasm,organelles and cell nuclei to work.Many researches have suggested possible protective effects of hydrogen on the body,but underlying mechanisms are unclear.It is generally considered that hydrogen can selectively counteract oxidation,regulate immune systems and interfere with cytokine expressions.Unlike common antioxidants,hydrogen can effectively and selectively scavenging hydroxyl radicals and peroxynitrite anion without affecting reactive oxygen species.How to apply it safely,efficiently and conveniently remains a challenge for scientists.