Aspergillus awamori var.kawachi produces three type of glucoamylase: raw starchadsorbable and -digesting GA Ⅰ(MW, 90,000; type A), raw starch-nonadsorbable and -nondigesting GA Ⅰ'(MW, 73,000; type B), and GA II(MW, 57,000; type C). The multiplicity of these glucoamylases and the specific conversion of the ability to digest raw starch were brought by the stepwise degradation of original GA Ⅰ by protease and glycosidases. A raw starch-affinity site which is composed of GP-Ⅰ(A^<470>-V^<514>)and Cp(A^<515>-R^<615>)regions on the GA Ⅰ molecule, was essential for raw starch-adsorption and raw starch-digestion. The GP-Ⅰregion promoted to digest raw starch and thus concluded to have the ability to hydrate raw starch. On the other hand, the Cp region has the ability to adsorb onto raw starch and cyclodextrins which were analogous to raw starch in terms of three dimensional structure. Adsorption onto raw starch of GA Ⅰ mediated by Cp region occurred in the formation of inclusion complex through the hydrophobic interaction. Therefore raw starch-digestion of GA Ⅰ was initiated by adsorbing onto and hydration of raw starch through the raw starch-affinity site. The well-hydrated part of starch molecule lost the affinity toward raw starch-affinity site, and hence starch molecule was captured by the active site located in GAⅠ' region. All raw starch-digesting amylases derived from other microorganism, bacteria, fungi, and yeast had the raw starch-affinity site and thus all amylases could be classified into two types whether the presence of raw starch-affinity site or not. On the basis of the affinity site theory, fungal endo-, and exocellulases were also classified into two types; C_1(Avicel-adsorbable, Avicel-digesting, and Avicel-affinity site-carrying) and C_x(Avicel-unadsorbable, Av icel-nondigesting and Avicel-affinity site-deficient). Trichoderma viride Exo Ⅰ(E^1-L^<496>, MW, 65,000) was limitedly proteolyzed into the two fragments, Exo Ⅰ'(E^1-G^<434>; MW, 56,000) and GPExo(G^<435>-L^<496>; MW, 9,000). The GPExo designated as Avicel-affinity site had intensive adsorbability onto Avicel but no catalytic activity toward cellulosic substrates. The Exo Ⅰ' showed identical activity to that of intact Exo Ⅰ toward cellooligosaccharides but was almost inert to Avicel in terms of digestibility and adsorbability. Thus domain structure and mode of digesting action of Exo Ⅰand glucoamylase were surprisingly similar for these microcrystalline carbohydrate substrates.