Abstract: Artesunate transdermal preparation at 5, 10, or 15 mg/kg, bid, for 3 days applied locally on the shaved skin of the back of monkeys showed reliable therapeutic effects on Plasmodium cynomolgi, but recrudescence of the parasites was not controlled. If some azone was added in the artesunate transdermal preparation at the dosage of 5 mg/kg, bid, for 3 days, the parasitemia of plasmodium cynomolgi could be cleared and recrudescence prevented, thus, the antimalarial effects was enhanced.