Reef tallow was hydrolyzed with lipase under the conditions of liquid state and solid state. Lipase OF 360 was used for that purpose, and the lipase had the maximum activity when the olive oil was used as a substrate at pH 6 and $37^{circ}C$. Beef tallow was dispersed by an agitator to perform a liquid enzymatic reaction. Water content, reaction temperature, and enzyme amount were varied as parameters affecting hydrolysis percentage. Ninety three percents of tallow were hydrolyzed at the following conditions: water content 80% w/w, temperature $37^{circ}C$, and enzyme amount 200 unitlg tallow. In order to conduct a solid phase enzymatic reaction, sonication was employed for pretreating tallow with the enzyme solution. Molten tallow was sonified with the enzyme solution, and solidified by lowering temperature. And then hydrolysis reaction proceeded at $30^{circ}C$. Sonication intensity and time were varied to control hydrolysis percentage. Optimum values of the intensity and the time were found to exist since the hydrolysis percentage did not increase further according to the increases of the intensity and the time.