Abstract:Pomacea canaliculata (Lamarck) is one of the most serious pests to the rice production area in southern China. In order to solve the problem caused by synthetic chemical molluscicides which are extremely toxic to the environment and agricultural products, we studied the efficiency of controlling P.canaliculata with four kinds of substitutes, calcium oxide, ammonium bicarbonate, Camellia oleifera powder and tea saponin, in laboratory and plot. The results indicated that the better control efficiency achieved using tea saponin, C.oleifera powder and calcium oxide. The mortality of snails achieved to 100% when the concentration of tea saponin was 40 mg/L and 50 mg/L, and treated for 48 h in laboratory. In the plot, mortality of snails were 100% using tea saponin at 6.0 g/m2 with 4 days or 1.5 g/m2 lasted 16 days. The quick-acting and lasting effect were better than those of other substitutes. Control efficiencies of C.oleifera powder at 30 g/m2 and 45 g/m2 and calcium oxide treatment at 45 g/m2 are over 80% after 15 days. In addition, these three kinds of substitutes can control the Echinochloa crusgalli (L.) Beauv effectively in the rice paddy. Ammonium bicarbonate was less effective on controlling P.canaliculata, and can promote the occurrence of E.crusgalli. We concluded that tea saponin, C.oleifera powder and calcium oxide can be used as the substitutes of synthetic chemical molluscicides for contro- lling P.canaliculata in the rice paddy.