-The different aspects of ecology of Mertensiella caucasica Waga, 1876 were investigated in a local population from Borjomi Canyon (central Georgia) for five years (1985-1990). The aspects of the species' life cycle were more precisely determined. The main fecundity is about 16.9 eggs per female. There are about 2 years in a period from egg deposition (June to first half of July) to the end of metamorphosis in nature. Animals have spent most of the time in shelters after metamorphosis. They appear on the ground surface at night during the breeding period. Commonly the adults don't retreat to a great distance from population localities. Localities are situated in comparatively small plots (100-300m) along the streams. Estimation of adult animal number showed that the population consists of 1189 specimens (1989). Annual adult survival is higher than known values of most amphibians (approaches 0.77). Larval survival is 0.27-0.32 in the second year of life. The characteristics of demography (especially, low renewal rates) and spatial restriction in localities depends mostly on subUe constitution of the species (which is a result of allometric growth specifics). The small recent geographical range of M. caucasica is explained as a result of morphological and ecological peculiarities. General morphological constitution limits adaptive possibilities of any particular representative of die European salamander tribe. This is an explanation of quite high ecological similarity of M. caucasica and Chioglossa lusitanica.