Objective To review the recent anatomy and biomechanical research progress of knee posteromedial corner, to analyze deficient aspect, and to predict future research directions. Methods Domestic and international l iterature about the anatomy and function of knee posteromedial corner in recent years was reviewed extensively, at the same time, the biomechanics of corresponding structure was summarized and analyzed. Results The anatomical structures ofknee posteromedial corner included the static stabil ity structures and the dynamic stabil ity structures. The dynamic stabil ity structures were more important, including posterior root of medial meniscus, posterior obl ique l igament, semimembranosus extensions, meniscotibial l igament and obl ique popl iteal l igament. The posterior obl ique l igament was most important structure to contribute to stabil ization of valgus, anterior internal rotation of knee and posterior movement of tibia. Conclusion Anatomical reconstruction of knee posteromedial corner especially the posterior obl ique l igament is the key to the reconstruction of knee posteromedial function stabil ity.