Objective: To explore the protective effect of highland barley (Hordeum vulgare L. var. nudum Hook.F.) on the hematopoietic function of irradiated mice. Methods: After feeding with 20% highland barley diet for 12 weeks， C57BL/6J mice were irradiated with 60Co-γ rays at a dose of 4 Gy once， then continue to raise two more weeks. The body weight， food intake， peripheral blood image， bone marrow and spleen tissue morphology， bone marrow nucleated cell count， organ index and blood biochemical level were monitored to evaluate the recovery of hematopoietic function. Results: Compare with irradiation group， the body weight of the mice in highland barley intervention group was significantly recovered on the 4th day after irradiation， the food intake in the 1st week was significantly increased. Also， total cholesterol (TC)， bone marrow nucleated cells， red blood cells， hemoglobin， white blood cells， and blood lymphocyte cell levels were significantly recovered， and the bone marrow structure had no significant damage. At the same time， highland barley intervention could effectively prevent the abnormal organ index and protect the spleen structure after irradiation. The studies have shown that the preventive intervention of highland barley can prevent the damage to immune function by reducing the damage of spleen tissue morphology， the abnormality of white blood cells， lymphocytes， organ indexes and blood biochemical levels after irradiation. And protect hematopoietic function by recovering the damage of bone marrow structure in mice after irradiation， and promoting the recovery of bone marrow nucleated cells and peripheral blood red blood cells. Conclusion: The preventive intervention of highland barley is to effectively recover the hematopoietic damage caused by radiation through protecting the immune function of the body.