This study used chitosan deacetylated to different degrees to process woolen fabrics via the nano-metrization of sodium hydroxide of different concentrations. The analysis and determination of the bacterial resistance, shrink resistance, Fourier transform infrared, and dyeability were then carried out for the processed substances. The particle diameter was measured with light scattering and scanning electron microscopy. It was then reduced with 5% and higher concentrations of NaOH, in which the particle diameter was 150-750 nm. As for bacterial resistance, the processed cloth that was not oxidized by H2O2 had better bactericidal and bacteriostatic effects than the cloth that underwent the oxidation process. Chitosan and meso-chitosan had a bacterial-resistance effect on the woolen fabrics. The processed cloth also had a better shrink-resistance rate, but the effect of nanometrization was not obvious. For the dyeability of the woolen fabrics, meso-chitosan was better than chitosan. The higher degree of deacetylation of chitosan slightly improved the dyeability. The dyeability increased a little as the temperature of the curing treatment rose and the time of the curing treatment was extended. (c) 2006 Wiley Periodicals, Inc.