The purpose of the master's thesis was to determine the population structure of Saccharomyces strains from Primorska wine region. Among the 356 strains isolated from vineyards and forest areas, we identified 27 different species. As a genotyping method, we characterized allelic variation at 11 hypervariable microsatellite regions which can distinguish Saccharomyces cerevisiae strains by their geographical and technological origin. We studied the correlation between the genotype of the strains and their habitat, the geographical location and phenotype. S. cerevisiae strains isolated from vineyards in the wine region of Primorska did not form a homogeneous group distinct from others. However, strains from a few of the geographic locations were genetically similar. Saccharomyces paradoxus showed a lower genetic diversity than S. cerevisiae. Based on the number of different alleles at the same microsatellite locus we detected a high degree of tetraploidy in S. cerevisiae and a high degree of triploidy in strains isolated from vineyards. We also studied the adaptation of strains to the oenological conditions by comparing growth rates in the presence of ethanol and copper and sulfur compounds. In addition to Saccharomyces, some other species such as Hanseniaspora uvarum, Torulaspora delbrueckii, Pichia kluyveri and Pichia kudriavzevii are well adapted to such conditions.