The pharmacological and clinical effects of gelatin capsule of Artemisia annua (GCAA) were investigated. The results revealed that the LD50 was 162.5 +/- 10.1g (crude drug)/kg and ED50 was 11.9 +/- 2.4g (crude drug) for clearance of parasitemia in mice infected with Plasmodium berghei therapeutic index being 13.6, which was 3.5 times more than that of artemisinin. The cure rate of COEA for Plasmodium berghei and P. vivax infections was 100%, as well as just like that of the extract tablets of Artemisia annua and chloroquine. This formulation was found to be better than chloroquine in fever subsidence and disappearance of malarial symptoms, while the recrudescence rate was still high, the latter could be inhibited by increasing therapeutic course or daily dosing time or by combination with primaquine.