The present invention relates to a Li-rich antiperovskite compound and the use thereof, and more particularly, to a Li-rich antiperovskite compound having a novel structure in which a dopant is substituted in a Li3OCl compound, wherein the dopant is substituted for an O site rather than an anionic Cl site, as known in the art, and an electrolyte using the same. The Li-rich antiperovskite compound has high lithium ion conductivity and excellent thermal stability, and thus can be applied as an electrolyte for lithium secondary batteries which are driven at a high temperature.