In recent years, use of chitosan (CS) nanoparticles as nanocarriers received much attention due to their bio-degradability, biocompatibility and non-toxicity. Water-soluble sulfated CS derivatives are widely used as anticoagulant and antiviral drugs. The chitosan sulfates (CSS) containing one-to-three sulfate groups were investigated using 0the DTF. The energy gap [Formula: see text], electronegativity ([Formula: see text]), electron affinity (EA), chemical potential [Formula: see text], ionization potential (IP), hardness [Formula: see text], softness [Formula: see text], electrophilicity index [Formula: see text], and maximum charge transfer index [Formula: see text] were obtained by the B3LYP/6-31++G(d,p) method. The electronic and thermodynamic properties, Mulliken atomic charges of sulfated chitosan with different contents of sulfate groups were obtained using the B3LYP/6-31++G(d,p) method.