When raw silk fibers and fabrics were treated by the sericin fixing agents of melamine-formalin mixtures, it was found that raw silk fibers must be fixed below $80^{circ}C$ to prevent the sericin damage and the effective sericin fixation of raw silk fabrics can be obtained from fixing by the comparatively small concentration of fixing agents. The melamine-formalin mixtures of above 0.3% of formalin fixed sericin stably and excellently because melamine can cross-link sericin at three positions effectively. The dye uptakes of sericin fixed raw silk fabrics were slightly increased with increasing the concentration of melamine-formalin for sericin fixation because a part of three amino groups of melamine which were not transferred into methylol group by formalin can be the dyeing sites of raw silk fabrics. The simultaneous fixing sericin and dyeing silk in the liquors of melamine-formaline containing acid dye resulted in very poor dye uptakes because of the acid dyeing hindrance of excessive melamine.