The moisture absorption and moisture retention properties of polygonatum polysaccharides, fenugreek polysaccha-rides, chlorella polysaccharides and ganoderma lucidum polysaccharides were investigated as compared with propylene glycol and water. The results showed that polygonatum polysaccharides had similar moisture absorption properties as propylene glycol, but its moisture retention was significantly better than that of propylene glycol. Therefore, the desorption process of tobacco under low humidity conditions was fitted nonlinearly by common thin-layer drying models. It was found that the tobacco added with polygonatum polysaccharides have the lowest drying rate constant and the slowest moisture retention rate. Low field nuclear magnetic (LF-NMR) results showed that, the addition of polygonatum polysaccharides reduced the physical bound water content where as the chemically bound water content in tobacco was increased. Therefore, polygonatum polysaccharides could be used as a natural and efficient humectant in tobacco to prevent the loss of moisture during storage.