At the results of investigation of micromorphology features of seed surface of the Portulaca oleracea aggr. (Portulacaceae Juss.) from Chernivtsi Region (Ukraine) six morphotypes of this taxa were recorded. Some peculiarities of the seed morphology of Portulaca L., and features of the ultrastructure of seed surface of the P. oleracea aggr. morphotypes, based on the results of micromorphological studies with using electronic scanning microscope was described. The general for the representative of the genus (e.g. globous, ovate or almost reniform shaped of seeds; black or dark brown color) and specify for the morphological types (star-shaped, isodiametric or elongate cells of seed surface with central part and long or short rays; smooth surface of seed or with knobs (from 0,03 mm in diameter) or papillae (0,01–0,02 mm), etc.) peculiarities are determined. The original scanning electron microscopy (SEM) photographs of seed surface ultrastructure of the studied morphological types and key fragment for its determination are suggested. According to our investigation six morphotypes of Portulaca oleracea aggr. are presented in Chernivtsi Region. Some of them are new for studied territory (P. granulatostellulata (Poelln.) Ricceri & Arrigoni, P. papillatostellulata (Danin & H.G. Baker) Danin), and other (Portulaca nitida (Danin & H.G. Baker) Ricceri & Arrigoni, P. trituberculata Danin, Domina & Raimondo, P. tuberculata (Danin & H.G. Baker) Danin) – new floristic records for Ukraine, and one of them (P. oleracea) – was known before also. The maps of distribution of this morphotypes in the region are presented. At the results of morphotypes distribution the most common is P. granulatostellulata and P. oleracea – rare in studied region like as in Europe also.