For the first time in Ukraine the investigations of the orchard, forest and field biocenoses with purpose to reveal nematodes of Steinernematidae and Heterorhabditidae lines have been performed. Entomopathogenic nematodes were found in the most biocenoses. The frequency of occurrence of Entomopathogenic nematodes in field biocenoses was higher than in the orchard's ones. Different types of the orchard and forest cenoses were inhabited irregularly with Entomopathogenic nematodes. In Forest-steppe, Woodlands zones and Carpathian zone of Ukraine family Steinernematidae was dominated, representatives of genus Heterorhabditis – in the Crimea. The total percentage of contaminated samples in the regions and the Autonomous Republic of Crimea was 22,8 % and 5,47 % respectively.