A process for preparing compounds of chitosan saccharified with aminosugar, adopts chitosan derivatives, aminosugar derivatives and anhydride derivatives as raw materials to synthesize target products. The process comprises: covalently bonding an anhydride derivative as a bonding arm to an aminosugar derivative, so as to form a monosaccharide derivative having an end group of carboxyl; and then covalently bonding the monosaccharide derivative having an end group of carboxyl to a primary amino group of a chitosan derivative via the carboxyl, so as to form a compound of chitosan saccharified with aminosugar.