In this paper an attempt is made to study accurately, the potential and electric field distribution for different types of ceramic disc insulators used for high voltage transmission and distribution systems. The computer simulations are carried out by using a commercially available software package. The potential and electric filed results obtained for the actual insulator profiles for three types of Ceramic disc insulator's/strings are studied up to 400kV system voltage with and without corona control rings and the arcing horn. The simulation results obtained are analysed and presented. It is worth mentioning that some of the results obtained are presented for the first time.