In this study, maleic anhydride（MA） and glycerin were used as modifiers for treating poplar wood. The effects of maleic anhydride content, reaction temperature and time, as well as esterification temperature and time on the stability of the treated wood were investigated.The results showed that anti-volume swelling efficiency（ASE） of the wood samples reached 91.02% by optimum treatment processes such as 100% maleic anhydride content, below 90 ℃ reaction temperature for 4 hours and 100 ℃ of esterification temperature for 4 hours. Esterification between maleic anhydride with hydroxyl groups in both wood and glycerin was verified by FT-IR analysis and SEM observation.Therefore, it was concluded that the maleic anhydride and glycerol reacted with each other in the cell cavity and formed an esterified substance, resulting in reduced porosity and better dimensional stability of the wood samples.