objective: To study the effect of betulinic acid on blood parameters in mice and provide a scientific basis for the research of betulinic acid. Methods: KM mice were orally administered with betulinic acid for 14 days at the dose of 0, 0.25, 0.5 and 1 mg/kg body weight. Immune organ index, blood parameters and serum lysozyme activity were determined. Results: betulinic acid could enhance the immune organ index and increase the amounts of WBC, Lymph and RBC with a dose-effect relationship. In addition, betulinic acid could significantly incre...