Abstract: Grafting of pupa protein on oxidative viscose filament yarn was carried out with HIO3at pH value= 5.0,30℃for 2 h.The dosage of HIO3was 0.08 g/g viscose filament yarn.Its grafting percentage was 35.1%.The cross-linking treatment of the grafted silk was conducted with 10% glyoxal at 30℃,pH=4.0 for 3 h,thereby obtained milk white grafted silk with pupa protein content of 5.24% and single fiber breaking strength of 2.9 N,that is only 8% lower than that of viscose filament yarn.No pupa protein released in acetic acid or in NaHCO3solution with pH value= 3.50 or 9.50 respectively.Infrared spectrum analysis showed that the grafted silk has a special absorption of Schiff bases and has a brilliant shade when dyed with methyl red.