In order to explore the safety of Yedahuang powder extract in clinical application,Kunming mice were selected as the research object to carry out acute toxicity and subchronic toxicity tests.The median lethal dose(LD₅₀) and maximal tolerable dose(MTD) of Yedahuang powder extract were measured in acute toxicity test. 2,10 and 20 g/kg of Yedahuang powder extract were used in subchronic toxicity test,respectively. The mice were given extract by gavage for 35 days to observe the clinical manifestations,calculate the organindex,detect the blood routine, serum biochemical and immunological indexes,and observe the pathological changes of organ tissues to determine the toxicity.The results showed that the LD50 could not be determined in acute toxicity test,and the MTD was ≥120 g/kg.In the subchronic toxicity test,compared with the normal saline control group, the lymphocyte number,the secretion level of sIgA in respiratory tract and intestinal tract and the level of IgG in serum of mice in the 10 g/kg and 2 g/kg dose groups of Yedahuang powder extract were significantly increased(P<0.05),and there were no significant pathological changes in the heart, liver, spleen,kidney and other tissues of each group.The results show that the extract of Yedahuang powder is a kind of non-toxic substance, and it is a safe Chinese medicine preparation.