Abstract: This research observed spalted wood (Populus sp., Alnus nepalensis, Betula alnoides, Pinus sp.) that had inoculated by Phomopsis sp. J9-1 and cultured for 12 weeks by polarized & fluorescent light and infrared spectroscopy. FTIR spectral analysis indicate all of the 4 species of spalted wood were degraded in different degree, a small quantity of degradation of cellulose or hemicelluloses have only occured in Populus sp. and Alnus nepalensis, the changes of functional groups of lignin have been found in every spalted wood, the aromatic rings and side chains of lignin in Populus sp. and Pinus sp. were partly degraded, slight degradation of side chains of lignin shown in Alnus nepalensis and Betula alnoides. There were no evident degradation and no significant changes of cell elements and chemicals in all spalted wood through polarized and fluorescent light, so the spalted wood can satisfy the conditions of decoration and artwork.