The fungus Diplocarpon rosae (anamorph = Marssonina rosae Lind.) is the causal organism of rose black spot, which is the most damaging disease of rose worldwide.On rose, black spots with fringed margins appear on either leaf surface but predominantly the upper surface of leaves. Infected leaves turn yellow, except for the black spots, and drop from the plant. Similar symptoms occur on petioles and fruit. Flower petals develop red spots and some distortion. Canes may become infected during the first year of development. The influence of different pesticides used in rosa on the growth of the fungus Diplocarpon rosae, a natural pathogen of Rosa, was evaluated under the laboratory conditions. The pathogen was grown on PDA (potato - glucose - agar) and Czapek Dox culture media in order to track its dynamics and preferences over nutrients. The fungicides studies were difenoconazol (Score 250 EC), miclobutanil (Systhane 12 E), cooper (Champ 77 WG) and boscalid + piraclostrobin (Signum 50 WP). Good results were obtained with difenoconazol and boscalid-piraclostrobin which inhibited growth of fungus.