The molluscicidal effects of 10% salt of quinoid- 2' ,5-dichloro-4'-nitrosalicylanilide (LDS) with dusting method, 26% amine molluscicide (MNSC) and 50% niclosamide (WPN) with insufflation method were tested in the fields of mountainous areas of Yunnan Province. After 7, 15 and 30 days of the tests, the death rates of snails, decline rates of living snail densities, and occurrence rates of frames with living snails of the 10% LDS group were 72.69%-87.16%, 74.10%-88.84%, and 20.00%-30.00%, respectively; those of the 26% MNSC group were 66.21%-91.06%, 69.55%-91.36%, and 19.44%-27.78% respectively; those of the 50% WPN group were 78.10%-90.18%, 82.44%-91.60%, 17.50%-20.00%, respectively. The results showed that the molluscicidal effects of 10% LDS, 26% MNSC and 50% WPN were basically equal.