Polymeric surface with regular patterns of protuberances developed recently has shown high performance compared with traditional adopted smooth surface because it shows limited discharge activity and lower ageing marks. For this reason, the knowledge of the potential and the electric field distribution is very important to assess and estimate the insulating surface performance and to enhance the power system reliability. This work presents an attempt to study the behaviour of electric field and the potential distribution on the surface of different conventional and textured insulating surfaces in order to improve the long term performance of polymeric insulator surface. The numerical 3D simulation has been conducted using COMSOL Multiphysics software based on finite element method. The results show how the configurations and diameters of the hemispherical protuberances influence on the geometrical characteristics of different patterns. Moreover, the effect of studied textures on the electric field and the potential distribution has been presented.