Abstract. Picea jezoensis wood block was degraded by a white-rot fungus (Porodaedalea pini) under laboratory condition for different periods up to 120 days. Chemical composition changes of the wood caused by white-rot fungus degradation were evaluated by Fourier Transform infrared (FTIR) spectroscopy. Additionally, discoloration of the wood meal was analyzed using colorimeter by calculating CIELab values. The results showed that the constant value in the relative changes of lignin and carbohydrates band ratio, indicating that P. pini degrades lignin and carbohydrates nonselectively, with a slight preference for lignin. Fungus degradation of wood resulted in rapid color changes (L* value) that correlate well with degradation of lignin. This study also showed that FTIR spectroscopy is a very simple and fast method fore valuating wood degradation.