The activity of candida Sp lipase(CSL) in catalytic hydrolysis of olive oil has been investigated in W/O reversed micelle of AEOT/isooctane/water system and compared with that of AOT/isooctane/water system. The results indicated that the activity of lipase in AEOT/isooctane reversed micelles was about 2 times that in AOT/isooctane reversed micelles in the optimum water content(W 0=12) and pH=7.2, and the maximum hydrolysis rate(V max) increased nearly 3 times.