Population growth from year to year increases rapidly. This has an impact on increasing the supply of electrical energy to consumers. The thing that causes of increasing energy which is supplied to consumers are business, industry, and household. Therefore, a truly reliable distribution system is needed in maintaining electrical power contamination to the consumer. To maintain the contingency, special handling is required such as large scale maintenance management improvements and quick handling, in case of disruption. This sort of thing will minimize the disruption of the distribution network. Some parameters which are used as reference for the measurement of the distribution system is by using mode of SAIDI (System Average Interruption Duration Index) and SAIFI (System Average Iterruption Frequency Index), where in the calculation results can be in the data value SAIDI and SAIFI, compared to the standards which are used, those are the reliability standard SPLN 68-2 1986 and IEEE standard std 1366-2003. Based on calculations, the largest SAIFI value of Rayon Jepara in 2014 is on JPR02 feeder, with the value 0.384. In 2015, the highest SAIFI value of Rayon Jepara is on JPR04 feeder, with 0.36 of value. Then in 2016, the largest SAIFI value is on JPR02 feeder which reaches 0.322 of value, and in 2017, the largest SAIFI value is on JPR03 feeder, it is 0.127. These values can still be categorized by trusted standards of SPLN and IEEE. In 2014, the highest SAIDI value is on JPR04 feeder with a value of 0.342 hours. In 2015 the highest SAIDI value is on JPR01 feeder with a value of 0.296 hours. In 2016, the highest SAIDI value of Rayon Jepara is JPR02 feeder with a value of 0.346 hours, and then in 2017, the highest SAIDI value Rayon Jepara is JPR01 feeder with a value of 0.243 hours. These values are still categorized as reliable because they do not exceed the SPLN and IEEE standards.