Abstract: In this paper, the toxicities of four new pesticides on Rana limnocharis tadpole were tested, and their safety pre-evaluations were made.the results show that these pesticides are low-toxic to frog. Since the application time of propachlor is consistent with tadpole growth period of the frog,it is suggested that measures should be taken in order to protect tadpole from propachlor wheen it is applied.