In Indonesia, electrical energy is one of the energies needed for human beings. With the increase of electricity energy users in the Indonesian region, it is identical to the widespread electricity users to the community. To be able to add service to the community, PLN can increase the continuity of electricity distribution to customers. A reliability index is essentially several parameters that indicate the level of reliability of the distribution system by calculating the average number of interruptions during the year or SAIFI, the average system disruption index duration over the year, and The average interruption duration of a customer or CAIDI. The method used to calculate the reliability level of the power distribution system can use MATLAB, which later serves as a calculator to calculate the reliability index of the power distribution system. Based on the results of the calculations, it can be known that the reliability value of the recycling in the Kentungan substation in 2019 can be said to be reliable for the value of SAIFI according to SPLN No. 68-2:1986, WCS (World Class Service) and WCC (World Class Company). Whereas according to IEEE STD 1366-2003 can be said to be less reliable. For the value of SAIDI on the Kentungan Substation in 2019, according to IEEE std 1366-2003 and WCS (World Class Service) and WCC (World Class Company) is said to be less reliable, while according to SPLN No. 68-2:1986 can be said to be reliable. As for the value of CAIDI in the Kentungan Substation in the year 2019 can be said to be less reliable according to the IEEE STD 1366-2003 standard.