Background: This study sought to investigate therapeutic effects of hydrogen-rich saline (HRS) combined with hyperbaric oxygen (HBO2) in an experimental rat model of acute lung injury (ALI). Method: Forty male Sprague-Dawley rats were randomly divided into sham, LPS, LPS + HBO2, LPS + HRS, and LPS + HBO2 + HRS groups. After an intratracheal injection of LPS-induced ALI, the rats were given a single-agent HBO2 or HRS or HBO2 + HRS treatment. The treatments were continued for three days in this experimental rat model of ALI. At the end of experiment, the lung pathological, inflammatory factors, and cell apoptosis in the pulmonary tissue were detected by Tunel method and cell apoptosis rate was calculated accordingly. Results: In the groups treated with HBO2 + HRS, pulmonary pathological data, wet-dry weight ratio, and inflammatory factors of pulmonary tissues and alveolar lavage fluid were significantly superior to those of the sham group (p≺0.05). Cell apoptosis detection revealed that no single agent treatment of HRS or HBO2, or combination treatment, could alleviate all cell apoptosis. HRS combined with HBO2 treatment was superior to single treatment (p≺0.05). Conclusion: HRS or HBO2 single treatment could decrease inflammatory cytokines release in lung tissue, reduce the accumulation of oxidative products and alleviate apoptosis of pulmonary cells, then lead to positive therapeutic effects on ALI induced by LPS. Furthermore, HBO2 combined with HRS treatment presented a synergy effect on cell apoptosis decrease and a decline in inflammatory cytokine release and related inflammatory product generation, compared with a single treatment.