Electron beam pretreatment of used newsprint, pulp, as well as pulp recovered from clarifier sludge and paper mill sludge, caused the dissociation of cellulose from lignin, and rendered them suitable for enzymatic hydrolysis. A maximum dose of 1 MGy for newsprint and 1.5—2.0 MGy for pulp and paper mill sludge was required to render cellulose present in them in a form which, could be enzymatically saccharified to 90% of completion. Saccharification approaching the theoretical yield was obtained in 2 days with a cellulolytic enzyme system obtained from Trichoderma reesei. As a result of irradiation, water soluble lignin breakdown products, NaOH- soluble lignin, free cellobiose, glucose, mannose, xylose and their polymers, and acetic acid were produced from these materials.