Dactylis glomerata L. is a worldwide-cultivated species for its high yield, good quality and shade resistance. China also holds an extensive distribution of wild Dactylis. However, reports on researches on Dactylis glomerata are still rare. This review summarized the morphological, cytological and molecular diversities of Dactylis glomerata. Genetic polymorphism of Dactylis glomerata exits at all levels. It can be predicted that Systematical studies on genetic diversity of wild orchard grass rich in China should be very important to reasonable conservation, utilization and breeding of new varieties of Dactylis glomerata.