The bacterial cellulose was fermented by Gluconacetobacter xylinum G31 strain in HS medium (Hestrin Schramm). The fermentation products were preliminarily proved to be cellulose by anthrone colorimetry method and enzymatic hydrolysis method. The morphologies and structures of BC were characterized by FTIR, SEM, XRD, CP/MAS 13C-NMR, DSC and TG and their properties were tested. The results showed that the fermentation product was bacterial cellulose.It had an ultrafine three-dimensional network structure and belonged to cellulose type I with a crystallinity of 92.42%, and had good water-holding and stretchability. At the same time, its molecular weight was measured (Mw=5737) and showed that it belongs to low molecular weight BC. Its oxygen transmission rate and water vapor transmission rate were 913.55?3.23 cm3/m2?24h?0.1MPa and 656.15?3.92 g/m2?24h respectively, indicating the BC has better water-holding capacity and lays a foundation for its application in the mask field.