Abstract. A comparative analysis of the monographs on Plant substances and Semisynthetic substances included in the European Pharmacopoeia 8 (Ph. Eur. 8) was made regarding their chemical structure and the group of active substances to which they relate. Theanalysisshows a continuousincrease in the number of monographs on thesegroups of substances (from 147 articlesinPh. Eur. 4 to 377 inPh. Eur. 8).Theyconstituteabout 19.5 % of thetotalnumber of monographs in the Ph. Eur. 8.The total number of monographs on plant substances is 123, of which the largest is the number of alkaloids (46), followed by mono-and polysaccharides (29), terpenes (11) and organic acids (10). From the group of alkaloids are included 13 monographs on isoquinoline, 8 on indole, 7 on alkaloidswithnitrogenatomintheside-chain,6 on tropane and 5 articles on purine alkaloids. Thetotalnumber of monographs on semisynthetic substancesis 254. From them 58 are derivatives of various higherfattyacids, higherfattyalcoholsandlipids; 57 are articles on derivatives of alkaloids; 44 monographs are on mono-anddisaccharides (mainly derivatives of gluconicacid) andsugaralcohols (mainly sorbitansandpolysorbates); 33 are on homopolysaccharides (mainly cellulose derivatives); 14 are on heteropolysaccharides; 22 are on phenoliccompounds (mainly derivatives of hydroxybenzoicacid); and 16 articles on nonaromaticorganicacids.There are 16 monographs on indole and ergoalkaloids, 13 on isoquinolinealkaloids(12 of these semisyntheticproductsaremorphinealkaloids), 11ontropanealkaloids, 6 onpurine alkaloids and 5 are the articles onanalogues of ephedrine.