The invention discloses a pharmaceutical composition for treating leukemia or aplastic anemia, and the pharmaceutical composition comprises American ginseng, Chinese caterpillar fungus, dragon's blood, pangolin scales, musk, bezoar, pearl, Hawksbill Carapace, palourde powder, prepared nux vomica, toad venom, toad skin and the like. The pharmaceutical composition is mainly used for treating various types of acute and chronic leukemia, aplastic anemia and thrombocytopenia. The pharmaceutical composition has the effects of clearing heat-toxin, promoting blood circulation, removing blood stasis, stopping bleeding, promoting production of blood and activating hematopoietic function. Furthermore, the pharmaceutical composition has the advantages of convenient administration, easy absorption, rapid onset of action, good effect, low cost, no toxicity or side effects and the like.