In this study TiO2-poly (methyl methacrylate-co-butyl acrylate) core shell nanoparticles were synthesized using microemulsion polymerization technique. Prepared nanoparticles were utilized as a toughening agent in Poly (vinyl chloride) inorder to improve its impact properties. 5% loading of Impact modifier gave the 41% improvement in tensile strength and 33 % improvement in modulus. Impact strength also increased constantly, result shows no break even at 1 %loading. Core-shell nanoparticles were found to have very good toughening effect on PVC, due to better interaction happening between acrylate and PVC polymeric chains.