This article focused on the series of Poly(Methel Methacrylate) /Polypyrrole Nanocomposite that prepared by insitu polymerzation method and the relationship between PPy content and the properties of their nanocomposite were analyzed.using 4point probe and TGA analysis. The result showed that the amount of PPY is a key factor for improving the thermal and electrical properties of nanocomposite. Furthermore thier thermal propertiese were analyzed by thermal gravimetric analysis(TGA) demonstrate that PPY nanoparticle improved thermal properties of nanocomposites. DSC analysis showed that decrease in the glass transition temperatures occured due to the addition of PPy due to decrease of segmental motion of PMMA chain.