This book includes my lecture notes for electrical power transmission course. The power transmission process from generation to distribution is described and expressions for resistance inductance and capacitance of high-voltage power transmission lines are developed used to determine the equivalent circuit of a three-phase transmission line. The book is divided to different learning outcomes Part 1- Describe the power transmission process from generation to distribution. Part 2- Develop expressions for resistance inductance and capacitance of high-voltage power transmission lines and determine the equivalent circuit of a three-phase transmission line.