recently, homogeneous synthesis of functional carbohydrate polymers carried out in ionic liquids (ils) has attracted extensive consideration because high reaction efficiency can be achieved. the objective of our work was to develop a new strategy to prepare acid anhydrides-modified xylan by the esterification of xylan with different types of acid anhydride such as acetic anhydride and succinic anhydride under the optimal dissolution condition of xylan in 1-butyl-3-methylimidazolium chloride ([bmim]cl) ionic liquid. significantly, effect factors on the xylan dissolution in [bmim]cl ionic liquid such as the concentration of xylan and the temperature were comparatively investigated, and the dissolution mechanism of xylan in [bmim]cl ionic liquid was revealed the physical and chemical properties of regenerated xylan were characterized by with various techniques such as ft-ir. and gpc as well as tga. under the optimal dissolution condition of xylan in [bmim]cl, different acid anhydrides-modified xylan was comparatively discussed in the presence and the absence of catalyst. it was found that catalyst has different role in the chemical modification of xylan with different types of acid anhydride due to the chemical structure of acid anhydride.