AIM: To study the effect of oral artemether (Art) in controlling schistosomiasis in endemic area of mountainous type. METHODS: Eight natural villages in Yanghe District, Yongsheng County, Yunnan Province were selected as the pilots. In the pilot, the infection rate of snails and the mean infected snail density were 0.38% and 0.0086/0.11 m², respectively, while the schistosome infection rate of the residents was 18.2%. The 8 natural villages were divided randomly into Art group and the control group by paired method. The residents aged 3-60 who contacted with infested water frequently were selected as the study objects and the residents were treated orally with praziquantel after stool examination. A single dose of 50 mg/kg was given to the egg-positive residents and 40 mg/kg was given to those with egg-negative. In the last ten-day period of May, i. e., 15 days after the residents contacted with the infested water, the first dosing of Art and the placebo (starch) was given at a single dose of 6 mg/kg to the residents in Art group and the control group, respectively, according to double-blind method. Afterwards, the same dose of the 2 drugs was given once every 15 days for 10 times. Stool examination was made in the residents of the 2 groups one month after the last medication for evaluation of the prophylactic efficacy. RESULTS: In Art group, the egg-positive rate was 2.9% (23/789), while in the control group it was 12.1% (87/717). The difference between the 2 groups was statistically significant. Besides, 1 case of acute schistosomiasis was seen in the control group, but no infected case was found in the Art group. CONCLUSION: In heavily schistosomiasis endemic area of mountain-ous type, oral Art given to the residents once every 15 days throughout the whole transmission season resulted in an apparently decrease in reinfection with schistosomiasis and effective control of schistosomiasis.