In order to increase the anti-bacterail property of tussah silk fabric, a nano-material dispersion system contained titanium dioxide nano-particles, chitosan, 1,2,3,4-butane tetracarboxylic acid, sodium monophosphate and surfactants was prepared. The particles in the dispersion solution have a narrow particle size distribution with average particle diameter of approximately 40 nm. Tussah silk fabric was then modified with the dispersion system using a conventional pad-dry-cure method. The structure of the modified tussah silk was characterized by X-ray photoelectron spectroscopy (XPS). The anti-bacterial efficiency of the treated tussah silk fabric with the dispersion system at a concentration of 0.2% nano-titanium dioxide and 0.5% chitosan showed over 99% of bacterial reduction against the Staphylococcus aureus（S. aureus） and gram-negative bacterium Escherichia Coli (E. Coli). In addition, the anti-bacterial reduction was maintained over 90% even after being exposed to 20 consecutive launderings.