Objective: To investigate hygroscopicity of carbohydrate composition in Yiganning aqueous extract. Method: With Yiganning grain as a model drug

total polysaccharides

total monosaccharides and total oligosaccharides were obtained by different separation and purifycation method

and then drying

crushing

hygroscopic percentage and critical relative humidity(CRH) were determined.HPLC-ELSD was used to detect carbohydrate composition by gradient elution method. Result: CRH of Yiganning extract was 67.3%

CRH of total polysaccharide

total monosaccharides and total oligosaccharides were 78.4%

62.2%

68.3%

respectively.Main components of total monosaccharides was fructose

small molecules carbohydrate in oligosaccharides was fructose

glucose and sucrose. Conclusion: Carbohydrate components was one factor of increasing hygroscopicity in Yiganning dry extract

hygroscopicity of fructose was largest.