Reproductive structures of Dictyopteris latiuscula from the Pacific coast of Kanto, Japan and reproductive seasonality in Shimoda, Shizuoka Pref. were studied. This is the first report of female gametophytes and oogonia of the species. Mature sporophytes and gametophytes were simultaneously collected in late spring to early summer. Reproductive season of the species was differed between Chiba and Shizuoka.