Lipase（EC 3.1.1.3）from Candida rugosa(Syn. C. cylindracea) was immobilized on the polyacry-lamide-gel(Bio-Gel P-10) by covalent binding. Since the substrates, triglycerides with ong chained fatty acids, are insoluble in water, emulsification of the substrates is necessary for lipase to react. Emulsions containing gum arabic were prepared by homogenization followed by sonication. Tributyrin and triolein were chosen as the substrates in order to compare the reaction properties in terms of the fatty acids chain-length. Kinetics of the enzymatic hydrolysis by soluble and immobilized lipases of tributyrin and triolein have been investigated in a batch-reactor. Soluble lipase was inhibited severely by the substrate at higher concentration of substrate emulsion, whereas immobilization of lipase reduced the substrate inhibition. This was especially true for triolein. Effects of pH and temperature on the lipase were studied. Thermal stability of the lipase was increased considerably when the lipase was immobilized.