Abstract: By paper chromatography, the tissue homogenate of Oncomelania snails was shown to form glutamic acid at the expense of a-ketogiutarate pms asparuc acia,aialmine otarginine respectively. The existence of alanine-glutamate, aspartate-glutamate and arginine-glutamate transaminase in Oncomelania snail was demonstrated.By using colorimetric method, the activity of aspartate-glutamate transaminase(GOT) and alanine-glutamate transaminase (GPT) of Oncomelania snail was 1.64±0.01 and 0.99 ± 0.01μmol/h·mg protein respectively. GOT and GPT were not inhibited by 2ppm bromoacetamide, but the activity of GPT was suppressed (40 %) by 2ppm nicotinanilide. A combination of 0.5ppm bromoacetamide and 0.5ppm nicotinanilide had no synergetic molluscicidal effect (Fig. 1).