The rapid development of technology and modern life. The people are in need of electricity as a source of energy, hence the need for energy that is quality and efficient, to provide it required three step of electric power distribution that is generating, transmission and distribution causing some problem that is loss of power loss in transmission channel and also distribution. Power loss loss analysis from the Sragen substation to the Masaran at high voltage transmission 150kV can be done with the data retrieval voltage and current. Calculation method by recording the change of voltage and current every day at 10.00 and 19.00 WIB for one month. Transmission of Substation Sragen to Substation Masaran using ACSR type 246/40 wire conductor. the conclusion of the loss loss calculation result is the highest loss of power loss during the day of 0.3702918 MW on the 14th and no loss of power loss occurred on the 21st, 22th, 26th. The night occurred on the 16th of 0.3602844 MW. This research can be obtained that the loss of power that occurred during December 2017 amounted to 136065,4065 kWh and caused losses of PT PLN (Persero) valued at Rp 159,795,213.