Hydroxypropyltrimethyl ammonium chloride chitosan were prepared by the reaction of chitosan and 2, 3-epoxypropyltrimethyl ammonium chloride. The Structure of HACC was characterized by infrared spectrum, and it was proved that substitution reaction mainly occurs on the -N element. The DS, stability in different pH and its antibacterial function of the product were studied. The preparation method of HACC antibacterial paper was also taken into consideration, and the antimicrobial function of the resultant paper is proved.