Abstract
Bulgaria is one of the European countries with the greatest biodiversity, including biodiversity of medicinal plants. The object of this study is the Zemenska Mt, located in the Western Bulgaria. As a result of our investigation, 423 medicinal plants belonging to 273 genera and 78 families, were found. The predominate life forms are hemicryptophytes (61.10%). Biological types are presented mainly by perennial herbaceous plants (61.00%). The most numerous are Euro-Asiatic floristic elements (18.67%). There are 27 protected species and 26 tertiary relicts. Anthropophytes among the medicinal plants are 34.52%.