Abstract: On 31 st March 2015, the tripping of a heavily loaded 400 k V transmission line located in the corridor between Turkish eastern and western subsystem led to the disconnection of the Turkish power system from the European network of transmission system operators for electricity（ENTSO-E） CE grid and eventually resulted in this widespread blackout. Firstly, the basic condition of Türkiye Elektrik ?letim Anonim ?irketi（TEIAS） including generation mix and management pattern as well as the development history of synchronization with ENTSO-E, was introduced. The system conditions prior to the blackout, sequences of events, oscillation of grid frequency and process of system restoration were reproduced in this paper based on data from high-resolution WAMS system and power quality devices installed in Turkish and ENTSO-E power grid. Through detailed analysis of the mains causes concerning the relay protection, grid maintenance, on-line monitoring system and national grid code, several suggestions from technical, structure and management aspects are proposed to ensure the reliability and stability of China Power Grid, as well to prevent severe blackout accidents in the future.