The hydrolysis of triacylglyceride by reversed micelle of the lipase was studied. The enzyme was solubilized in reversed micelle of bis (2-ethylhexyl) sodium sulfosuccinate (25 mM, AOT) in isooctane and water (0.31\%). The enzyme activity depended on the molar ratio of water to AOT (R value), and maximum activity was observed when the ``R value`` was 7. It is remarkable that under the conditions investigated, the reaction rate in the micelle was ca. 6 times faster than that in aqueous emulsion system. The pH-activity profile showed that optimum pH was 7.3 in isooctane-AOT micellar solution. Optimum temperature was at $30-35\,^\circ\!C$. Also, Ea, activation energy was 7.9 Kcal/mole. When ``R`` value was seven, apparent Km and Vmax for olive oil were 0.80\% and 51 uM/mg/hr, respectively. In the enzyme stability against isooctane, the relative activity of the lipase entrapped in AOT-isooctane rapidly dropped to ca. 50\% after 2 hours. The order of the reaction complied with 2nd order reaction.