Reliability is the performance rate of a system to distribute continuously to a customer. When the distribution system was a disrupted that can be disturbing for continuity of electricity distribution. The objective of this study is to analyze the reliability of power distribution system of 20 kV in PLN Banjarnegara district at 2016. The data being used is secondary data from the total data costumers every feeder in PLN Banjarnegara district at 2016, the data of feeder disruption for one year, include: feeder disruption, duration of outages and a total number of customers disturbed in each feeder. Analysis or parameters used as a reference to knowing the reliability of a distribution system was SAIFI (System Average Interruption Frequency Index) and SAIDI (System Average Interruption Duration Index) by using Microsoft Exel. The reliability index values was compared to the standard used: SPLN 68-2 1986 standard, IEEE std 1366-2003, and World Class Company (WCC) and World Class Service (WCS) standards. Based on SPLN 68-2 1986, IEEE std 1366-2003. SAIFI and SAIDI that are smaller than standard value by SPLN 68-2 1986, IEEE std 1366-2003 and World Class Company (WCC) and World Class Service (WCS) standards.