N-(2-hydroxy-3-trimethylamine)　propyl　chitosan　chloride　(HTCC)　nanoparticles　were　prepared　through　two-step　method　using　chitosan　with　low　molecular　weight　and　high　degree　of　deacetylation.　H　of　-NH2　of　chitosan　was　replaced　with　quaternary　ammonium　salt　groups　to　form　HTCC.　HTCC　was　further　modified　by　ion　sol-gel　reaction　with　sodium　tripolyphosphate,　the　reaction　can　be　in　the　dispersion　under　the　action　of　Span-80,　and　the　ionic　bonds　formed　between　phosphate　group　of　sodium　tripolyphosphate　and　the　amino　group　in　HTCC　main　chain,　well　dispersed　HTCC　nanoparticles　with　a　average　diameter　of　23.6nm　were　than　obtained.　The　structure　was　characterized　with　fourier　transform　infrared　spectrum　(FTIR).　When　HTCC　nano-particles　were　applied　to　contact　with　staphylococcus　aureus(S.　aureus)　and　escherichia　coli　(E.　coli),　the　results　showed　completely　under　the　condition　of　antimicrobial　resistance.　©　(2014)　Trans　Tech　Publications,　Switzerland.