The education gap has been the most important research topic since the beginning of school education, and much research has been done in Korea. However, with the socioeconomic polarization, the polarization of educational investment is intensifying, and the belief in the possibility of hierarchical migration through education is also weakening, and it continues to emerge as a social issue. Most of the major researches carried out so far have been carried out for the purpose of improving the educational gap, but the approach of research is very diverse. In this study, we analyzed trends in educational gap research. According to the results, the concepts of educational gap and similar concepts such as education inequality and education alienation are mixed and utilized, and the factors influencing education gap are comprehensive, And measurement tools have not been developed by consistent standards. Therefore, efforts to resolve and improve the education gap in the future should be logically linked with research and actual policy development.