The palinomorphological features of six species of the genus Hypericum (H. аlpigenum, H. elegans, H. hirsutum, H. maculatum, H. montanum, H. perforatum) of the flora of Ukraine have been investigated. All species studied are valuable medicinal plants. However, only two species of raw material are officially permitted: H. perforatum and H. maculatum. Raw materials of other species can also be harvested from natural habitats, as they are wide spread in some regions of Ukraine and morphologically similar to pharmacopoeial species, but their admixture to the raw materials reduces its quality. The aim of research was to make a comparative morphological analysis of pollen grains six species of genus Hypericum of Ukrainian flora for determine the common and distinctive features that will identify the species of raw materials. We used a scanning electron microscope to investigate the pollen grains ultrascultures (CEM, JSM 6060 LA). The studies were performed according to the standard method. As a result of palynomorphological studies of six species of the genus Hypericum of the flora of Ukraine established, that the pollen grains of the species studied are small-sized, 3-colporate, ellipsoidal or spheroidal, outline in polar view ‒ trilobate, rounded-triangular, in equatorial elliptical. In all studied species the colpi are long, mostly with distinct margins, pointed ends and a granular membrane. The pores are undistinct. Sculpture exine in the investigated species of the genus Hypericum of the flora of Ukraine are microreticulate (H. perforatum, H. alpigenum) and reticulate (all other species studied). Morphometric features of pollen grains of the studied species: the length of the polar axis, equatorial diameter, colpus width, mesocolpium width, the diameter of the apocolpium, the ratio of the length of the polar axis to the equatorial diameter, the ratio of the mesocolpium widths and aperture widths can be used as additional diagnostic features in identification species of the genus Hypericum of Ukrainian flora.