Sericin in adhesive silk waste water from Amphur BanPai, Khon Kaen was purified through the repetitive precipitation by dissolving in sodium thiocyanate and precipitating by ethanol. The positive resulted of Biuret test confirmed the proteins precipitant. Gel electrophoresis showed that the sericin has molecular weight larger than 97 kDa. Study of the sericin’s nanofiber was prepared by Electrospinning.