A novel thermoplastic konjac glucomannan(TKGM) was synthesized with KGM and methyl acrylate(MA) initiated by ammonium persulfate. The percentage grafting (PG) and the grafting efficiency (GE) was affected by concentration of initiator and monomer, temperature, and time. The results indicated that the percentage grafting (PG) and the grafting efficiency (GE) can attach 70% and 90% at optimal conditions, respectively. The structure and properties of TKGM were characterized by FTIR and DSC. FTIR results demonstrated that graft copolymerization was occurred between MA and KGM. The results of DSC indicated that a new glass transition temperature (Tg) of TKGM at 16.4°C was appeared compared with KGM with no glass transition temperature. It suggested that product of TKGM can be made through thermoplastic process.