The effectiveness of highly compressed water as a pretreatment for the enzymatic saccharificationof sawdust was studied. Sawdust was compressed at 20 MPa in a high pressure-resistant steel vesselfilled with water. The efficiency of a subsequent saccharification process was increased with an increase in the temperature of the compressed pretreatment. The reaction time by compression was suffi cient within 24 hr. As a result, saccharifi -cation effi ciency was about 60% with the highly compressed water pretreatment at 50℃ for 24 hrs.