With recent development of enzyme engineering, the use of enzyme in organic solvents is rapidly increasing. The remarkable stereoselectivity and regioselectivity of reaction catalyzed by enzyme were used to resolve many racemic alcohols and esters. A number of results have also been reported about the resolution of amino acids in organic solvents. For example, DL-phenylalanine methyl ester was resolved by α-chymotrypsin in toluene/water biphasic system; in fact, this reaction was carried, out in water;transesterification of DL-phenylalanine propyl ester and methanol was catalyzed by α-chymotrypsin in methanol, and the enzyme used was dissolved in water and the pH