In order to obtain a method of scouring of raw silk and degumming of cocoon by the appling of bacterial enzyme of sericinase, a strain of proper bacteria was isolated and some properties of the enzyme produced by the isolated bacteria were studied and the following results were obtained. 1) Optimum pH and temperature were indicating 7.5 and $50^{circ}C$. and on these conditions, the silk fibroin will get no modification at all. 2) Sericinase activity was inhibited by calcium ion in the free incubation but same ions reacted as an activator in the reaction with substrate. So, degumming of Tussah cocoon which contains calcium oxalate in the cocoon layer will be possible by the treatment of this enzyme. 3) This bacterial sericinase never gives any affection to the fibroin layer of the silk. 4) The factors of smooth-surface condition, damage of fibroin layer, touching, luster and degumming effect of the silk resulting by the enzyme treatment were more appropriate than the results of other scouring methods, saponin, alkali and saponin-alkali using methods. We expect to get the same scouring result that compared with the papain or pancreatin were applied.