To compare the molluscicidal effects and cost-effectiveness of 5% niclosamide ethanolamine salt granules (NEG) and 26% suspension concentrate of metalaldehyde and niclosamide ethanolamine salt (MNSC) .Two plots with high snail density were selected as research areas in Nanjing Chemical Industry Zone, and 5% NEG (40 g/m) and 26% MNSC (40 g/m) were used by the spraying method for snail control in the two plots, and their molluscicidal effects and cost-effectiveness were investigated and statistically analyzed.There was no significant difference between 5% NEG and 26% MNSC in the molluscicidal effects. The cost of 5% NEG was 1.25 times higher than that of 26% MN-SC per ten thousand square meters in snail control.The cost of 5% NEG is higher than that of 26% MNSC per ten thousand square meters in snail control. Their molluscicidal effects are similar.