Abstract <p>The article considers the nature of the relationship between the synanthropization, structure, and diversity of complexes of dominant species in relatively large (0.15–0.2 ha) sites of vegetation with different histories and intensities of anthropogenic disturbances. The study was conducted in low-mountain and high-mountain regions of the Western Caucasus. The total number of studied sites was 161. Within each of them, dominant species were identified and their projective cover was estimated on 100–150 1-m² accounting plots laid out in a regular manner. The results showed that most parameters of the structure of dominant complexes are statistically significantly related to the level of their synanthropization. In particular, an increase in the values of this characteristic is accompanied by an increase in the frequency of occurrence of monodominant communities in sites, including those with a dominant species coverage of 60–80% or more. At the same time, the maximum diversity of dominant complexes is observed at average values of the synanthropization level. It is suggested that the parameters of the structure of dominant complexes may be useful as an additional tool when comparing the degree of anthropogenic degradation of large areas of vegetation cover.</p>