Abstract: Abstract:A method to immobilize Eudragit L100 covalently on the surface of proteases （Esperase 8.0L）reactive sites was reported.The main purpose of the preasented work was to use this proteases modified in the bio-finishing process of wool fibres,to target enzyme action to the outer parts of wool fibres,i.e.to avoid the diffusion and consequent destroying of the inner parts of the wool fibre structure in the case of native proteases using.The modified Esperase 8.0L was obtained by modification with carbodiimide (EDC) activated Eudragit L100.It's molecular weight increased from 4.1-6.5KD to 45KD. Modified enzyme have a benefit effect on the wool fibres felting behaviours,relativly to the enzyme（Esperase 8.0L）,weightlessness rate reduced by 21.9%, fabric tensile strength increased by 13.1%.Besides, the felt resistance of wool was significantly improved after finishing by the proteases modified,the area of shrinkage rate from 8.12% lower to 0.89% .

Key words: wool fabric , protease , enzyne modification , felting