Korean Spiraea can be rearranged into 10 species and two varieties except one species excluded here, S. media confined only in Mt. Baekdu. A key to the species, description and nomenclature are provided. In taxonomic treatment, the categories of three varieties, S. chamaedrifolia var. pilosa, S. pubescens var. leiocarpa and S pubescens var. lasiocarpa are not accepted because the trichome distribution, on which the varieties were based, is highly variable and is considered only within the limit of individual variations. S. microgyna should be treated as a separate species either from S. fritschiana or S, japonica based on flower color, leaf morphology and trichome distribution. It is revealed S. betulifolia does not distribute in Mt. Bukhan and hence excluded from Korean flora. Korean Spiraea shows four kinds of inflorescence which are important for delimiting sectional level and petal color, anther morphology, style position and follicle morphology are key characters for delimiting the species. Pollen is monad and tricolpate type with striate sculpture in surface and is uniform except size variation throughout the species examined.