In this study, wood chips of a native pulpwood, Sterculia setigera, was treated with two white-rot fungi genus of Pleurotus and Lentinus for a period of time lasting in 9 weeks. The effects of biodegradation on wood basic chemical composition were evaluated in this study. The extractive content increased from 6.3 to 10.3% for P. tuber-regium and to 15.7% for L. subnudus after 9 weeks incubation time. It was observed that both P. tuber-regium and L. subnudus degraded lignin and the lignin content of wood diminished 11.4 and 28.8% (relative percentages) after 9 weeks of incubation time respectively. The amount of inorganic matter (ash) observed was more for L. subnudus than for P. tuber-regium. The results indicated that both fungi could be used for biodegradation that preserved cellulose in S. setigera and this approach could be an environmentally friendly method in pulp and paper industry in Nigeria.