In preparing the “Keys to Plants of the Republic of Buryatia”, we have searched and systematized the literature sources on vascular plants. From various scientific publications, data on the findings of new plants at the territory of the Republic of Buryatia were extracted and analyzed. The study also found that the published works after the publication of the Key, significantly have changed the idea of the quantitative composition of the flora, which was replenished with 178 species, 1 subspecies and 10 hybrids of vascular plants from 44 families and 131 genera. The largest number of findings was recorded in the families Asteraceae (30 species, 16 genera) and Poaceae (30 species, 20 genera). The most representative genera were Carex, Hieracium, Pilosella, Polygonum.