Using N, N-dimethylformamide (DMF) as solvent, nitrated bacterial cellulose (NBC) solutions with different nitrogen contents were prepared according to a certain proportion. The effects of solution concentrations and nitrogen contents of NBC on the viscosities of NBC solutions and the dependence relationship of concentrations and viscosities of the solutions were studied by a HAAKE rotational rheometer, and the viscoelasticity of NBC solution was analyzed through its stress scanning and frequency scanning. Results show that the solution system is the Newtonian-fluid when the concentration of NBC solution is in the range of 0.5%-5.0%, and the viscosity increases as the increase of the solution concentration, meeting an exponential function growth relation. When the concentration of NBC solution is 5.5%, NBC solution is the non-Newtonian fluid, showing a shear thinning effect, and the shear stress and shear rate meet a power function growth relation. The viscosities of NBC solutions increase with the increase of NBC molecular weight. NBC with high molecular weight helps to improve the stability of the solution system and makes it less response to external stimulus.