Objective: To prepare the acetylated Sophora alopecuroides polysaccharide (AC-SAP)

and study the conformation characteristics of the modified acetylated S. alopecuroides polysaccharide solution. Method: S. alopecuroides polysaccharide was modified by acetylization

and the modification results were verified by means of the substitution determination method and infrared spectroscopy analysis. The conformation characteristics of acetylated S. alopecuroides polysaccharide was studied by I2-KI reaction and Congo red test. Solution behavior of acetylated S. alopecuroides polysaccharide under different conditions were studied by circular dichroism (CD) spectrum. Result: Acetylated S. alopecuroides polysaccharide was successfully modified and its substitution degree was 0.84. Its solution behavior indicated multiple helixes structure with long side chains and many branches in solution. In addition

its solution conformation could be affected by the concentration

temperature and metalions. Conclusion: Comprehensive research on the solution conformation of successfully modified acetylated S. alopecuroides polysaccharide can provide reference for further research.