Photograft copolymerisation of methyl methacrylate (MMA) onto mulberry silk fibre has been done in limited aqueous medium using cerrous ammonium sulphate (Ce+3)/potassium persulphate (K2S2O8) as the redox initiator and compared with the graft copolymerization done in dark under the same conditions. Grafting, total conversion, grafting efficiency and pH dependency of the system have been studied and analysed. The mechanism of polymerisation and graft copolymer formation are discussed. FTIR spectra and SEM studies show the evidence of grafting on the fibre backbone.