The genus Micrerethista Meyrick, 1938 belong to the subfamily Harmacloninae, comprises 11 described species for the world. Adult are usually very small to medium in size (wingspan, 4-16mm). The principal apomorphy of this genus, the denticulate projection of the aedeagus, easily distinguishes it from most Harmacloninae. In this study, we dealt with the genus Micrerethista is newly recorded from Korea for the first time, with one species. Illustrations of adult and genitalia are presented.