Earthquake Early Warning ( EEW) comes into the sight of people as a result of unreliability of earthquake prediction． The paper illustrates comprehensively the research status and hot issues of EEW in terms of the concepts，compositions and methods． The study of the government status，social needs，network building and research foundations reveals that it is a right time to build EEW in Chinese Mainland． It also estimates the technical difficulties and nontechnical challenges in the course of the implementation of EEW in China，and suggests the enhancement of legal measures，public education and seismic protections to bring the Earthquake Early Warning system into full play in earthquake relief．