Abstract: The activity component in Ambrosia artemisiifolia was extracted with ultrasonic method and then the mice was fed through pouring the fluid into stomach. The organophosphorus pesticide DDVP and blank treatment were taken as control. The purpose of this research was to study the extracting solution of A. artemisiifolias effects on the activity of CarE and protein content of mammals. The results showed that extracting solution of A. artemisiifolia had the effect of activation on CarE. The enzyme activity value increased to 15.006 μmol/（min•mg） markedly during 6 hours after feeding pesticide. Then it decreased gradually and reached 9.156 μmol/（min•mg）, which was basically recovered to normal until 24 hours after feeding. Apparently, DDVP has the effect of inhibition on the activity of CarE of mice liver. The activity of CarE was in the state of inhibition after feeding pesticide and the value was lower than control and recovered slowly. Furthermore, both of extracting solution of A. artemisiifolia and DDVP have the effects of inhibition on protein content of mice liver. Therefore, as pesticide and antibacterial agent, the safety of the activity components of A. artemisiifolia is better than organophosphorus pesticide.