A gradual change in the state and properties of the oil transformer due to aging, which generally leads to break down. Aging of the mineral oil cause permanent harmful change of the ability insulation system. Aging of the mineral oil and water content of paper insulation are simulated at the laboratory by putting the samples of the oil and pieces of insulation paper in a rig (transformer manufactured) and exposed to different temperatures (20Co, 40Co, 60Co, 80Co) for specific durations of time to analysis and improve the performance of the transformer. In this research, the electrical and physical characteristics for the mineral oil and paper insulation have been studied and then repeated by the addition of different concentration of Nanoparticales (ZnO) (0.01, 0.03, 0.05, 0.07)gm/ml then compared with the electrical properties of the pure mineral oil and paper insulation without (ZnO) nanoparticales