Abstract: Researches regarding the acute and sub-chronic toxicities of artificially fermented Cordyceps sinensis(AFCS) were conducted in this study. LD₅₀ of oral AFCSin both rat and mice were over 10 g/kg BW. After 90 d feeding of wealing rats ,all dosed animals grew and developed well and the average body weight of each dosed group was slightly higher than that of controls. The routine blood test, serum biochemical measurements, organ/body ratios and pathological examinations of major organs of rats were also determined in this study. The results showed that there was no difference between these indexes of dosed groups and that ofcontrols. The results demonstrate that AFSC is basically a toxicity-free and safe substance for rats.

Key words: Cordyceps sinensis, toxicology, sub-chronic toxicity