Abstract: 54 cases of chloroquine-resistant falciparum malaria were treated with a single dose of 300mg artemether (i.m.) combined with 1, 000mg of sulfadoxine, 70mg of pyrime thamine and 30mg of primaquine orally (ASPP) in an endemic area of Hainan Island. Fever was controlled readily in 25.6±15.0 hours. The asexual blood parasites and gametocytes disappeared in 30.2±12.5 hours and 48.2 + 6.9 hours respectively. Only mild side effects were observed in few cases.As compared with other three therapeutic schemes including single dose of ASP (omitted primaquine),QSPP (0.5gm Qinghaosu i.m. instead of artemether) and chloroquine alone for 3 days, the action of ASPP and ASP appeared more rapid than QSPP either in symptom control or in eliminating asexual forms of P. falciparum. No recrudescence was seen in the combined treatment groups. Chloroquine alone had less effect, 24 out of 50 cases were not cured and 17 showed a recrudescence of parasitaemia within 35 days after treatment. The authors concluded that a combination of either ASPP or ASP is satisfactory in the treatment of chloroquine-resistant falciparum malaria.