Five kinds of commercial ramie and hemp fabrics were treated with cellulase under different concentrations. Samples were mercerized before enzyme treatment to investigate the effect of mercerization on cellulase enzyme treatment. Physical characteristics(weight loss, tear strength retention, wrinkle recovery, drape stiffness, dyeability) of cellulase enzyme treated and untreated samples were measured and compared. X-ray diffractions were examined to verify if there were any changes in their crystallinity of enzyme treated fabrics. Weight loss, wrinkle recovery and degree of crystallinity increased as the concentration of cellulase enzyme increased. In the meanwhile, tear strength retention and drape stiffness and dyeability decreased. Enzyme activity was more effective on mercerized samples. Particularly, there was distinct tendency to increase weight loss and flexibility.