AIM To explore the protection effect of Blood-Replenishing Capsule (BRC) on hypoxic animals in order to lower the rate of altitude stress. METHODS Comparison of BRC on survival time of mice under ordinary pressure and chemical hypoxia were observed and the oxygen consumption was measured. RESULTS BRC-obviously prolonged the survival time of hypoxic mice, reduced the oxygen consumption and increased the hemoglobin (Hb) content in the bloods.Mouse brain's SOD was obviously higher and MDA concetration remarkable lower in BRC groups than those in control groups. CONCLUSION BRC shows remarkable effect on hypoxia tolerance in mice.