A yellow crosslinking polymeric dye was prepared by grafting the flavone moiety containing azo chromophore onto polyvinylamine backbone. The lambda(max) of this polymeric dye in water is 382 nm. The polymeric dye is fixed to silk and cotton with a crosslinking agent, 2-chloro-4,6-di(aminobenzene-4'-beta-sulphatoethylsulphone)-1,3,5-s-tria zine, which acts as a bridge between the fiber and dye molecules. The fixation of this polymeric dye reaches 99% and the dyed samples exhibit excellent rubbing and washing fastness.