Abstract: The hot-reaction was tested and analyzed between wheat straw, EVA, PE and PVC by DSC. The result showed that two decalescence peak appears in the DSC curve from the composite of wheat straw-EVA. There is a difference of melting point between the composite of wheat straw-EVA and EVA. Moreover, the Tg of the composite of wheat straw-EVA was difficult to confirm in DSC curve, and the Tg of EVA was relative evidence in 33.4~50.5℃ according to the analysing of the vitrification temperature Tg. There is a difference of one between the composite of wheat straw-PE and PE. The former melting point is 131.5℃ and the latter is 132.9℃, if the apex of decalescence peak is the melting point. Besides the former decalescence content is 93.3% that of the latter. The vitrification temperature Tg of PVC is near 70℃. Moreover the vitrification temperature Tg of the composite of wheat straw-PVC is a difficult to ascertain. Furthermore there is bigger contrast of the melting point for two materials. One decalescence peaks appears in the DSC curve of PVC and the melting point is about 86.0℃. There are two decalescence peak of the composite of wheat straw-PVC, and its melting point is not clear. The reaction status can be known between wheat straw, EVA, PE and PVC by the hot-reaction analysis of melting point and vitrification temperature Tg.