Abstract: Both nicotinanilide hydrochloride and nicotinanilide sulfate are water-soluble, their LC50 and LC90 against Oncomelania snails being around 0. 3mg/L and 0. 5mg/L, respectivly, during 24 hour exposoure at 25℃ followed by a 7-day recovery period. The laboratory tests and field trials showed that over 90% of snails were killed within 3 days exposure at 1-2mg/L, and that 18.4%-100% snails on moist soil were killed at over 20℃, exposed to spraying dosage of 1-2g/m2 for 1-3 days. The chemical is highly effective against snails eggs at early stage (cell stage). The LC50 of nicotinanilide to Aristichthys nobilis and Pseu-dorasbora parva is about 200mg/L. The acute oral LD50 in mice is about 2g/kg. Plants tolerate the chemical at 1-2g/m2, but some leaves wilted at ≥5g/m2, dicotyledon in particular. Dermatitis has been reported in individuals frequently exposing to nicotinanilide wettable powder during massive spraying.