Within the field seasons of 2019-2020, new localities for seven vascular plant species listed in the Russian Federation Red Data Book were recorded (Ajuga pyramidalis, Cypripedium calceolus, Dactylorhiza baltica, D. traunsteineri, Isoetes lacustris, Lobelia dortmanna, Myrica gale) as well as for 20 species listed in the Leningrad Region Red Data Book (Actaea erythrocarpa, Asplenium trichomanes, Betula humilis, Carex bohemica, Crepis sibirica, Diplazium sibiricum, Equisetum scirpoides, Hierochloe australis, Lathyrus laevigatus, Ligularia sibirica, Lonicera caerulea, Petasites frigidus, Pulsatilla patens, Ranunculus subborealis, Rubus humulifolius, Trichophorum cespitosum, Trisetum sibiricum, Viola selkirkii, Viscaria alpina, Woodsia ilvensis). The floristic studies were carried out in the planned nature protected areas (NPa) of the Leningrad Region: «Chagoda», «Upper reachers of the Sondala river», «Motornoe-Zaostrovie», «Karelian forest», «Oyayarvi-Ilmenjoki» and the their surrounding territories. New data allow to better assess the level of the planned NPas’ conservation value and could be later used for the federal and regional Red Data Books re-publications. Based on the current data on the protected species distribution the recommendations on economic activities restrictions within the valuable areas and their buffer zones are made.