The biological degumming of silk fibers was studied using alkaline proteases such as Savinase and Alcalase, comparing with conventional alkaline treatments. Degumming efficiency was evaluated by measuring the residual silk sericin in terms of weight loss and surface staining with reactive dye. The water absorbency and tensile strength were measured to characterize surface and physical properties, and the results are presented. The dosage was the decisive factor in enzymatic degumming process. Finally, the morphology of silk fibers was researched by scanning electronic microscopy, and the regular removal of sericin and less damage to fibroin were detected in enzymatically treated fibers.