It is well known that the commonly used granular enzymic digestives are easy to diminish it`s potency through preparation and custody. We made an experinent to know the proper way of manufacturing and keeping the granules without a loss of potency by Ls orthogonal Tables. The factors, we considered, decomposition of enzyme activity through manufacturing are ① sufficiency of granules drying ② with or without sodium bicarbonate (NaHCO₃) in gramules ③ separate wet granulation of enzyme and the rest of the component or mix together ④ kind of packing materials (Polycello or quartet silner paper) Besides we counted ⑤ humidity ⑥ temperature as block factors. Then we tested the potency of each sample by intervals of a week, 2 weeks and we foretelled the potency of after one year by the life test. From the experimental results, main factor of activity loss is preserving humidity. Therefor the sufficiency of packing is became a main problem and the granules have to be made by separate wet granulation to inhibit it`s decomposition. Temperature is the factor that accelerates loss of activity by humidity but does not so much by itself mixing enzyme toge ther with NaHCO₃ is not became a matter so far as it is dried.