This a d d e mnmarks the achievements of the authors' groupin the area of biocatalyst-catalyzd organic reactions in recent 10 years. A strain of Gtohichum sp. obtained by screening is capable of stereoselectively reducing a number of carbonyl ampounds. In many cases, the stereochemistry is complementary d t h that obtained by baker ' s yeast. Therefore, this microorganism provides a useful pathway to the preparation of dcohol compounds with specil'lc configurations. On the other hand, a number of plant sources have been screened for oxpnitrilases and the hydrocyanation reactions of various arylcarboxaldehydes have been investigated. A "micro-aqueous d o n system" ww invented. by which a series of novel optically active cyanohydrinq were prepared. On this basis, a high through-put continuous reaction system bas been designed. This paper also describes exampla of the syntheses of bio-active compounds by Using the optically active compounds obtained From the abovementioned catalytic reactions as precursors. , IC~YWOIYIS asymmetric synthesis, biocatalyst, Ceohichwn sp., stereoselective reduction, oxynitrilase , enantioselective hydrocyanation *