Com. Candida antarctica lipase and lyophilized cells of Yarrowia lipolytica KKP379 yeast were tested as catalysts of transesterification of vinyl stearate with pentanol. The reaction was used as test method to det. the synthetic activity of lipase. The results were compared with conventional spectrophotometric method by using p-nitrophenyl laurate as raw material. Similar results of synthetic activity of lipases were obtained for both test reactions.