Morchella is the famous medicinal fungi in the ascomycetes. In this study, a new water-soluble polysaccharide (MSP-3-1) with an average molecular weight of 2.35 × 107 Da was extracted and purified from fruiting bodies of cultivated M. Sextelata. The structural characterization and biological activities of purified polysaccharide was further investigated. The results indicated that MSP-3-1 was mainly a α-glucan, mainly consisting of mannose (Man), glucose (Glc) and galactose (Gal) in a ratio of 5.10: 91.39: 3.51. Its surface morphology exhibit...