Abstract: Objective To investigate the safety of aqueous extracts from Gynura divaricata, so as to provide a theoretical foundation for further research and development. Methods Preparing the aqueous extracts from Gynura divaricata, the LD₅₀, MTD were tested by the classical methods of acute toxicity. Five groups of Kunming mice were used for pre-experiment by different concentrations of aqueous extracts from Gynura divaricata, the survival rate of mice were observed, so as to determine the LD₅₀. Mice were given relevant drugs intragastrically every 4 h in 24 h in experimental group, at the same times the blank control group mice were given constant distilled water, and the general symptom, death and weight of mice were observed. Mice were sacrificed 14 days later, and blood was detected, and organs were observed by eyes, the liver and kidney were examined histopathology, and MTD was counted. Results The LD₅₀ of mice was not detected by the pre-experiment, the MTD of acute toxicity test was 120 g·kg^-1. The mice’s weight change was not significantly different between the control group and the experimental group (P < 0.05). ALT, AST, ALP, Urea, Cr, TP, ALB, Glu and T-Bil of mice were showed no obvious abnormalities. The pathological changes of liver and kidney were not obvious in the control group and the control group. Conclusion Aqueous extracts from Gynura divaricata had no obvious toxicity for Kunming mice.

Key words: aqueous extracts from Gynura divaricata, acute toxicity, maximum tolerance