Abstract: The thermal properties for the inorganic plastic crystals Na 2WO 4 were investigated by using DTA TG technique.The results obtained showed that the total enthalpy change in the solid solid phase change of Na 2WO 4 is 164.1 J/g.These indicate that Na 2WO 4 has good prospect.The mechnism of sdid sdid phase change is that the structure of Na 2WO 4 crystal changed low symmetry into high symmetry with the increasing of temperature,meanwhile,vibration and rotation become disorderly and absorb heat.