Abstract: A new practical method of preparing activated agarose support by isothiocyanate process has been developed. Alcohol dehydrogenase, lactate dehydrogenase and NAD were immobilized separately and coimmobilized site-to-site on isothiocyanate activated support. The enzyme activity yields of the immobilized alcohol dehydrogenase and lactate dehydrogenase were 9% and 12% respectively. The regeneration ability of the NAD with the coimmobilized tribasic enzyme system obteined here was four times as high as that with the corresponding free enzyme system.