Abstract: With high ornamental importance, the genus Iris is of great exploitation value. Iris mainly propagates by seeds; however, the seeds of most species exhibit dormancy characteristics, which makes them difficult to breed. Many causes account for this dormancy, including mechanical obstruction of the seed coat and the presence of germination inhibitors in the seed, thus affecting seed germination singly or interactively. Seed dormancy release methods typically include environmental, mechanical, chemical or hormone treatment. Here, we systematically review seed dormancy and its methods and mechanisms in Iris to provide a theoretical basis for the rational utilization and germplasm innovation of this genus.