In seawater instillation-induced ALI in rabbits, molecular hydrogen inhalation alleviated histopathological changes and cell apoptosis; decreased the malondialdehyde content and MPO activity in lung tissues; decreased the levels of TNF-α, IL-1β, and IL-6 in bronchoalveolar lavage fluid; and markedly improved lung endothelial permeability. The gene discussed is TNF; the disease is acute respiratory distress syndrome.