A mixture of molluscicidal saponin compounds was isolated from a methanolic extract of seed meal of Camellia oleifera and tested against Pomacea canaliculata. The most potent saponin fraction showed an LC50 value of 0.66 ppm. This was then used as a marker for quantitative analysis of active molluscicidal compounds in commercial oilseed camellia meals on HPLC fractionation. The active saponin content was found to be 0.25-1.26% w/w. Methanol was the preferred extraction solvent for analysis of saponin compounds from oil-seed camellia meal. The effect of oil-seed camellia meal on P. canaliculata in a field experiment was determined for three doses: 12.50, 15.63, and 18.75 kg/ha in terms of numbers of dead snails. After one day, all treatments containing oil-seed camellia meal killed 100% of the snails in the sample compared with just 3.8% in the control without any chemical additive. No rice plant damage was detected from any treatments with oil-seed camellia meal, and the dry grain yield was comparable to that of niclosamide treatment. Thus oil-seed camellia meals may be a useful molluscicide for organic rice production.