Races of the fungus Macrosporium solani Ell. et Mart., inducing tomato macrosporiosis, differ from one another with respect to sources of carbon, nitrogen, phosphorus and sulfur nutrition. Mono- and disaccharides and nitrates and organic forms of nitrogen were found to be most suitable for culture of the races. Addition of compounds containing phosphorus and sulfur to artificial nutrient media stimulates the growth of mycelium.