Introduction This distribution is almost conditional because there are also the pests in partially infected and a few infected regions (free zones). It is enough to mark this fact that phylloxera was found just 9 hectares of grape plantations, but now about 50-60% of plantations are infected with phylloxera (1). Material and methods The samples of grape sorts (Tabrizi, Khindoghni, Bayanshira, Madrasa) which infected with phylloxera have taken from viticulture plantations of Beylaqan region with the purpose of determination of species composition of microorganisms which is cause of rotting the roots of grapevines’ in Azerbaijan conditions. The separation from roots of grape and reproduction of phytopathogen and saphrotrophs root rotting microorganisms’ which is cause to rotting grapevines’ infected with phylloxera is carried out with the method preparing by P.N.Nedov (2, 3) with the purpose of creating complex artifi cial infection background. Results and discussions Root samples from infected by phylloxera grape varieties Tebrizi, Xindogni collected from farms of Beylagan region were analized and species composition of microorganisms caused to the second pathologic process-rotting were determined. The amount of microorganisms obtained from roots, of Tebrizi grape variety was 100%. The phytopathogenes belonged to Cylindrocarpon genus were 26%, whereas phytopathologenes of Gliocladium genus were 34%, whereas phytopathologenes of Fusarium genus were 28%. Also among phytopathologenes of this grape variety 4% were saprotroph fungi from Penicillium genus, 2% were fungi from Mucor genus, 3% were fungi from Molissia genus and 3% were fungi from Rhacodiella genus. Spreading rates of phytopathogens from Gliocladium (34%) and saprotroph fungi from Penicillium (4%) genera were wider. Pathogens obtained from roots, of Xindogni grape variety infected by pests were 100%. These were fungi from Gliocladium genus - 25,7%, fungi from Cylindrocarpon genus - 23,3% and fungi from Fusarium genus - 35%. There were 4% saprotroph fungi from Penicillium genus, 3% fungi from Mucor genus, 3% fungi from Molissia genus, 3% fungi from Rhacodiella genus and 3% fungi from Absidia genus on roots of grape variety Xindogni. As it seen spreading rates of phytopathogens from Fusarium genus (35%) and saprotroph fungi from Penicillium genus (4%) were many wider. Conclusions Phytopathogen fungus species: Fusarium, Gliocladium, Cylindrocarpon; phytopathogen bacterium species: Pseudomonas, Bacillus; saprotroph fungus species: Mucor, Absidia, Molissia, Penicillium and Rhacodiella caused rotting the roots of grape by phylloxera were determined in Beylagan region of Azerbaijan.