P. canaliculata is now a major rice pest in Asia. For snail management, it is therefore imperative to develop an effective and practical method which is relatively safe to the non-target organisms and to the environment. Recently much attention has been given to study the molluscicides from plants, because they might provide effective, locally produced, biodegradable and environment-friendly approach for controlling snail. In this study, cardiac glycosides from the fresh leaves of N. indicum were isolated and 100 g fresh leaves were found to contain 0.0402 g cardiac glycosides. Molluscicidal efficacy of Nerium indicum cardiac glycosides on P. canaliculata and its effects on rice seedlings were investigated under laboratory conditions, in comparison with known molluscicides niclosamide. The results showed that the mortality of P. canaliculata increased significantly with both increase in cardiac glycosides concentration and duration of saponins treatment. An increase in cardiac glycosides concentration from 10 to 40 mg/L resulted in increased mortality of P. canaliculata (from 20. 8 to 95.8%) at 48 h, compared to the control group. It is worth noting that 50mg/L cardiac glycosides exhibited 100% snail mortality at 48 h, which was comparable to that treated with 0.156g/L niclosamide. Snail mortality under saponins treatment was positively correlated with snail size. The molluscicidal efficacy of cardiac glycosides on h<10 mm of P. canaliculata was the highest among them, reaching 73.3% treated with 40 mg/L cardiac glycosides for 24h. The most resistant snails corresponded to those having a size of 20≤h<30 mm, 26.7% mortality was recorded at 40 mg/L cardiac glycosides exposure for 24h. The remaining rate of rice seedlings was directly proportional to cardiac glycosides concentration. Cardiac glycosides at a concentration of 5 mg/L had almost no effect on the remaining rate of rice seedlings. An excess of cardiac glycosides (≥10mg/L) caused a considerable increase in the amount of plants studied. For instance, the remaining rate of rice seedlings increased 3.2-fold under 40mg/L cardiac glycosides treatment compared to 10mg/L cardiac glycosides treatment at 48 h. The remaining rate of rice seedlings with cardiac glycosides was also dependant on snail size. At 30 mg/L cardiac glycosides treatment, remaining rates at 24 h for h<10mm and 20≤h<30mm snails were 88.9% and 53.3%, respectively. The effect of cardiac glycosides on the fresh weight of rice seedling was also studied by the method of water culture. Growth of rice seedling depended on the cardiac glycosides concentration used. Shoot fresh weight did not change significantly treated with 0 40 mg /L cardiac glycosides for 7 days. A significant decrease was only detected after the plants exposed to the highest cardiac glycosides concentration (50mg/L) for 7 days. In contrast, the roots suffered more severe than the shoots. Root fresh weight were not affected as cardiac glycosides concentration increased from 0 to 30 mg/L, then decreased significantly as cardiac glycosides increased from 40 to 50 mg/L. When exposure time extended to 14 d, the inhibition was weakened gradually and was significant only at 50 mg /L treatment for root fresh weight. However, niclosamide completely inhibited seedling development. These data indicated that cardiac glycosides could be an environmental friendly and effective molluscicide against P. canaliculata.