Abstract: The mechanism of sex determination in dioecious plants is a hot topic in reproductive biology, evolution and ecology, and so on. During recent years, the sex determination genes of several important crops, such as asparagus, kiwifruit and poplar, have been revealed and applied to produce sex-specific products. New germplasms with bisexual flowers have also been developed for molecular breeding. In this review, the genetic bases of sex determination were systematically analyzed from the aspects of sex chromosomes and sex-determination genes in dioecious plants. Subsequently, the epigenetic regulatory roles of non-coding RNA and DNA methylation in plant sex determination were discussed. Finally, it was suggested that further comparative studies of sex determination genes among different dioecious plants should be carried out. More efforts are also needed to pay on the epigenetic regulations of plant sex determination. This work will not only facilitate to understand the molecular mechanisms of sex determination in dioecious plants, but also help to expand the application values of sex determination studies.