A new biological cross-linker, microbial transglutaminase (mTGase), has been used to catalyze the immobilization of lactoferrin onto the wool fabrics, and the antibacterial properties of immobilized wool on both Gram-negative and Gram-positive bacteria are studied. It is found that the minimal inhibitory concentration of lactoferrin against S·aureus and E·coli is 0.5mg/mL and 0.25mg/mL respectively. As compared to the control sample, the amount of lactoferrin adhered onto the wool fabric improves from 4.87 mg . (g fabric) -1 to 12.96 mg . (g fabric) -1 , indicating that the crosslinking reaction initiated by mTGase can increase the amount of lactoferrin fixed onto wool fabric obviously. The ratios of bacteriostasis to S.aureus and E.coli of wool fabrics immobilized with lactoferrin are bound to be 57.95% and 69.96% respectively, showing good antibacterial property.