A series of blend films with different ratio of poly(4-vinylpyridine) (PVP) to lignin were subjected to dynamic DSC and TGA measurement under nitrogen atmosphere at various heating rates. DSC curves showed that the glass transition temperatures of these blends decreased with the increase of lignin content. TGA studies indicated that the lignin content produced obvious effect on the thermal stability of these blends. The kinetic model function of the thermal decomposition of these blends obeyed the Avrami-. The degradation kinetic parameters were also obtained.