Lipid substance from Pomacea canaliculata at different developmental stages was extracted using ethyl acetate.The extracted substance was purified with silica gel column chromatography and thin-layer chromatography(TLC).The antimicrobial activities of the separated compounds derived from effluent fractions of three different organic solvents(petroleum ether,benzene and ethanol)were tested against 11 bacteria.They have varying levels of antimicrobial activities,with the non-polar solvent showing the least activity and the strong polar solvent showing the strongest activity.The liposoluble compounds extracted by TLC from all of the bands of the ethanol effluent fraction exhibited variable antimicrobial activities.GC-MS analysis revealed that the most of the chemical components are the acid substances in the strongest of these antimicrobial fractions from different developmental stages.The same chemical component had different content and different similitude at different developmental stages of P.canaliculata.