Hematopoietic stem cells in bone marrow form all kinds of blood cells. In traditional medicine, functions of bone marrow cells are very similar to those of Essence(精) which is a fundamental factor of physical development and reproduction. Our experiment examined the effect of deer blood on aplastic anemia induced mouse using cyclophosphamide 150 mg/kg i.p injection before experiment and then another cyclophosphamide 120 mg/kg i.p injection on day 10. Then we administrated dried deer blood in distilled water for 5 days, 9 days and 10 days. We examined blood and marrow samples. In results, deer blood showed a trend of effectiveness on recovery of red blood cells and erythropoietin although they were not statistical significant. And deer blood did not show changes in CD34.