1. The study was conducted on the optimum condition of the treated substrate with dilute sulphuric acid solution and cellulase for saccharification. The wood (saw dust) of Alnus hirsuta Rupr. (10∼15 years) was treated with 0.3%, 0.6%, 0.9%, 1.2%, 1.5%, H₂SO₄ solution at 1.5㎏/㎠ for 15min., 30min., 45min., and 60min., followed by thermal treatment at 190℃ for 30min., and screening with 60 mesh sieve, after which to 0.5 grams of each sample was added 0.5㎖ cellulase solution, and 50㎖ 0.1M acetic acid buffer solution (pH 5.0), after incubating at 40℃ for 96hr. 2. The crude cellulase of Trichoderma viride Perx. ex. Fr. SANK 16374 was produced by the submerged culture process and produced in the culture fluid was salted out quantitatively by the use of ammonium sulfite. 3. Reducing sugar was determined by the 3.5-dinitrosalicylic acid (DNS) method. 4. The reducing sugar was increased with increase of the sulphuric acid concentration and saw dust was treated with 1.5% H₂SO₄ solution at 1.5㎏/㎠ for 45min. showed the best saccharification (16.0%). The reducing sugar formation did not show statistically significant in 5% levels by thermal treatment time 45min. and 60min. 5. The substrate for cellulase which was treated with 0.9% H₂SO₄ solution at 1.5㎏/㎠ for 60min. showed the best reducing sugar formation (23.6%). And did not show significant difference in 5% levels at 0.9%, 1.2%, and 1.5% H₂SO₄ solution.