PURPOSE: To improve the enzymic hydrolysis ratio of coniferous wood, e.g. pine or SUGI, by irradiating the coniferous wood with electron rays or γ-rays, blasting the wood, and if necessary pulverizing the blasted wood.

CONSTITUTION: Cellulosic wood is irradiated with electron rays or γ-rays at ≥106 rad and ≤108 rad, blasted and if necessary further pulverized. Coniferous wood such as pine or SUGI is finely powdered in a short time by pulverization to remove lignin from the surface of cellulose. Thus, the surface area of the cellulose is increased to improve remarkably the enzymic hydrolysis rate and hydrolysis ratio.