The main goal of this master's thesis is to introduce the reader to the modern way of managing electric power systems based on synchrophasor measurement technology, along a review of traditional ways of electric power system management. This master's thesis is composed of four sections that are elaborated in the following chapters: „Electric power system management based on SCADA systems“, „System monitoring based on synchrophasor measurement technology“, „WAMS implementation in Croatia“, „Future trends of system monitoring development“. In the chapter „Electric power system management based on SCADA systems“ traditional ways of managing electric power systems based on SCADA/EMS systems are described. In the chapter „System monitoring based on synchrophasor measurement technology“ synchrophasor measurement technology is presented, along with a managing system based on it – WAMS. Besides system architecture and applications, WAMS scope of use is reviewed and so are its benefits over traditional ways of electric power system management. Next chapter „WAMS implementation in Croatia“ elaborates WAMS now used in Republic of Croatia along with reasons of its implementation. Chapter „Future trends of system monitoring development“ describes the ability of upgrading WAMS with protection and control applications, together with a brief review of the future synchrophasor measurement technology development.