In this work, silk was grafted using dimethylaminoethyl methacrylate(DMAEMA) via activators regenerated by electron transfer for atom transfer radical polymerization (ARGET ATRP) method to produce well controlled grafted silk in water aqueous. CuBr2 was used as catalyst, N, N, N’, N", N" -pentamethyldiethylenetriamine (PMDETA) was used as ligand, vitamin C was used as reducing agent. The effects of monomer concentration, the proportion of catalyst and ligand, the variety and the dosage of catalyst and reducing agent, grafting temperature and time on the silk grafting were discussed, and the optimal grafting technology was obtained. FT-IR characterization of the grafted silk indicated that DMAEMA was grafted onto the surface of silk. The whiteness and permeability to gas of grafted silk slightly decreased. And the moisture permeability of grafted silk nearly had no change. The wrinkle recovery angle of grafted silk dramatically increased.