Thousands of waterlogged wood pillars beneath crop fields were discovered during the 2008 excavation of a 3,000 years archaeological site in Southwestern China.One segment of wood pillarwas sampled in 2009 for study.Specimens were studied with scanning and transmission electron microscopes, and 2.5 cm × 2.5 cm × 5 cm (length) specimens were dehydrated with methanol,followed bytreatment with low-molecular-weight neutral phenol-formaldehyde resin.The wood,identified to bePinuskesiya var.langbianensis (A.Chev.) Gaussen, was severely degraded by bacterial surface erosion and tunneling of cell walls.Bacterial tunneling was more frequently observed near the cell corners with thick walls.Bacterial degradation of cell walls was accompanied by accumulation of degradation prodncts and bacterial slime in cell lumens.Neither brown-rot nor soft-rot decay was detected in the wood.Stain fungi were found in rays and in adjacent tracheids, which are believed to be pre-existing prior to submerge.The wood sample gradually darkened after sampling, but removal of bacterial degradation products with methanol and a brief 2% oxalic acid treatment reversed the discoloration, The average specific gravity and crashing strength of the waterlogged wood were 0.245and 7.14 MPa, compared to 0.370 and 33.65 MPa of normal wood of the same species.Treatment of the waterlogged wood with neutral PF resin increased specific gravity to 0.435 and crushing strength to 12.75MPa.The PF treatment minimized shrinkage and warping and stabilized wood color of the waterlogged wood.Although the PF treatment is not reversible, the treated wood remains porous to allow retreatment.