Bagasse is an abundant agricultural byproduct. The use of bagasse has generated much interest due to its low cost, possibility of environmental protection and use of locally available renewable resources. In this paper, cellulose was dissolved in the ionic liquid （1-butyl-3-methylimidazolium chloride） and regenerated in water. FT-IR and SEM were used to characterize the structure of the original and regenerated cellulose. It was found that the treatment of the original cellulose in the ionic liquid significantly degraded the cellulose and completely destroyed the cellulose crystals. Despite many studies of the chemical modification of cellulose published around the world in this area, only a few have been investigated about the regeneration of sugarcane bagasse. Theoretical basis was established for further research on the application of the regenerated cellulose in material science.