Coix has a long cultivation history as a minor crop in China, but many problems including unclear origin, chaos of species, loss and inaccurate use of germplasm resources exist in its research and production due to the lack of systematic study. In recent years, the importance of Coix has been realized with the exploration of its effects in treating and preventing cancer. The systematic study of Coix has met a superb development opportunity with the rapid development of biotechnology especially the deep-sequencing technique. Therefore, this paper presented here the current status of origin and evolution, classification, cytology and molecular biology progress of Coix, analyzed the ploidy of Coix and the genetic relationships with Zea, Sorghum and so on from the point of cytology, and then based on the molecular biology, analyzed the important significance of DNA molecular marker, genetic mapping and gene library in the research on identification of genetic relationship between species and genetic breeding, which could provide useful information for further Coix research.
