The paper features the annotated list of vascular plants from the very poorly studied northern part of the Paanajarvi NP (Lake Sieppijarvi area) and adjacent territory (mount Sieppitunturi). A total of 268 species, including 6 hybrids, were found in the territory in question. The Park itself had 252 species including 5 hybrids. Minuartia biflora was a new find for Karelia, Diphasiastrum montellii, Viola epipsila var. hyperborea and Hieracium wainioi - for both Karelia and the park, Epipogium aphyllum and Hieracium diaphanoides - for the park. Thirty «red book» species were discovered, 4 of them listed in the Red Data Book of the Russian Federation (all within the park), 23 - in the Red Data Book of Karelia (17 within the park) and 23 - in the Red Data Book of East Fennoscandia (19 within the park).