Brief description of the history of investigation of liverwort flora of Hog land Island is provided. The list of 24 species newly recorded for the island (Anastrophyllum michauxii, Bazzania trilobata, Calypogeia fissa, Cephalozia loitlesbergeri, C. macounii, Cephaloziella elegans, C. hampeana, C. rubella, Diplophyllum obtusifolium, Isopaches alboviridis, Kurzia pauciflora, Lophozia sudetica, Metzgeria furcata, Mylia taylori, Nardia scalaris, Odontoschisma francisci, Orthocaulis floerkei, Riccardia chamedryfolia, R. incurvata, Scapania nemorea, Schistichilopsis laxa, Tetralophozia setiformis) is annotated by data on coordinates of their locations, habitats, growth pattern, associated species, known locations on adjacent territories, presence of structures associated with reproduction (gem. — gemmae and brood bodies, per. — perianths and other protecting structures of developing sporophytes, juv. caps. — juvenile capsules, caps. — mature capsules, anth. — antheridia). Species marked in the list by one asterisk (*) are published for the first time for the island, species marked by two asterisks (**) (Calypogeia fissa, Cephaloziella elegans, Isopaches alboviridis, Tetralophozia setiformis) — for the first time for the Leningrad Region, records marked in the list by exclamation mark (!) (Isopaches alboiviridis, Lophozia sudetica, Tetralophozia setiformis) are the most southern records for European Russia. Specificity of the liverwort flora of Hogland Island is demonstrated on the basis of analysis of frequency and activity of the rare species.