Abstract: In order to evaluate the security of dichroa febrifuga extractive,the acute toxicity of dichroa febrifuga extractive was tested in mice. After preliminary experiment to determine the dosage,60 mice were selected and divided into 6 groups. After giving medicine lavage and observing for 7 days,the acute toxic reaction was recorded and the LD₅₀ value and 95％ confidence limit of LD₅₀ were determined by the modified Karber’s method. The results showed that some mice appeared toxic reaction and death. No pathological change was found in the main organs by necropsy of dead mice. The LD₅₀ was 18.16 g/kg body weight and its 95% confidence limit was 15.35 to 21.49 g/kg body weight. The results demonstrated that the dichroa febrifuga extractive has lower toxicity and safety for clinical application.

Key words: dichroa febrifuga extractive; acute toxicity; mice