The urgent problem of the relaying protection in the modern AC/DC hybrid connected grid and the development of the wide area communication, the information process and the intelligent technology powerfully promotes the development of the technology of the wide area relaying protection (WARP), which has become a research hotspot that attracts extensive attention. Originated from the basic concept of the wide area relaying protection, this paper analyses the advantages, the effects and the functions of the wide area relaying protection. The two main approaches to realize the wide area protection, which are on-line adaptive setting (OAS) principle and fault element identification (FEI), are introduced in this paper. Aimed at improving the performance of the backup protection, the research content and the technology demand of the wide area protection are proposed, meanwhile, the basic principle and the algorithm of the fault element identification are introduced. At last, the scheme of the limited wide area relaying protection based on the existing pilot channel of the main protection is discussed.