Abstract: A novel material，thermoplastic konjac glucomannan (TKGM) was synthesized from KGM，vinyl acetate(VAc) for the first time in this research. This novel material is water resistant and degradable. The influence of different experimental conditions on the graft copolymerization was studied，and the optimal conditions were as follows：ammonium persulfate initiator concentration 12 mmol/L reaction time 3 h，reaction temperature 70 ℃，vinyl acetate concentration 0.52 mol/L. The structure and properties of TKGM were characterized with FTIR，DSC and torque rheometer. The results indicated that graft copolymerization reaction took place between KGM and VAc. The glass transition temperature (Tg) of TKGM was only 0.12 ℃，and there was a melting endothermic peak at about 165 ℃. The maximum torque was only 0.85 N·m，the plasticizing time was 44 s and the balance torque was only 4 N·m. These showed that the TKGM had a good plasticity processability.