Fermentation of carbohydrates and assimilation of carbon compounds were evaluated. The utilization of 18 specific carbon compounds was estimated in the investigation of each strains for differentiation of the species. From among 125 strains of fungi the following were found: Candida albicans (112 strain), C. famata (2), C. glabrata (1), C. guilliermondii (1), C. kefir (4), C. tropicalis (2). The activity of 19 hydrolases was investigated using API ZYM. Biotyping of Candida strains was done according to the Williamson classification (1986), modified by Kurnatowska (1998). All strains were isolated from the oral cavity, rectum, as well as from the materials collected during endoscopy in children.