In Japan 655 species in 142 genera of liverworts and 17 species in 6 genera of hornworts are recognized. Many nomenclatural changes, a number of new species and infraspecific taxa (subspecies or varieties) of liverworts and hornworts have been reported for the Japanese flora since our previous checklist published in 2012 which recognized 625 species in 146 genera of liverworts and 17 species in 6 genera of hornworts. Phylogenetic arrangement for Japanese liverwort and hornwort genera are provided and current accepted names of Japanese liverworts and hornworts are alphabetically listed with annotations. In the annotations, the taxonomy, nomenclature and synonymy of many of the accepted species and infraspecific taxa are discussed briefly, based primarily on recent literature sources published up to 31st December 2017 and the authors’ observation. Homotypic (nomenclatural) synonyms are indicated in the annotations by the symbol ≡and heterotypic (taxonomic) synonyms by the symbol =. Three new combinations: Solenostoma granulata (Steph.) T.Katag. & Furuki, Solenostoma orientale (Bakalin & Vilnet) T.Katag. & Furuki, and Solenostoma shinii (Amakawa) T.Katag. & Furuki are proposed. Dendrocerotales T.Katag. & Furuki, which lacked description since described, is formally validated. Pleurozia gigantea (F.Weber) Lindb. is excluded from the Japanese flora, because the original citation of the species from Japan turns out be an error. Information on fossil species of Japanese liverworts and hornworts including two liverwort species are also summarized.