Abstract: In order to increase the Modal fabric antibacterial property, a novel chitosan/Ag+ composite antibacterial is prepared by organic and inorganic compound method and applied to antibacterial finishing of Modal fabric . Using single factor experimental studies on the applicable concentration range of two antibacterial agents. The result of the Orthogonal experiment showes that the antibacterial rate of Modal fabric treated by the combination of 0.8g / L chitosan and 0.8mg/L in the PH 6.5 is more than 93%. Even after 50 laundering cycles the antibacterial rate has no significant decline. The damage of the strength and whiteness is small and the wrinkle resistance impoves instead.