To conserve biodiversity of amphibia in Ukraine it is necessary to understand the impact of human pressure on this group. Some recent publications permit us to do this. Comparison of populations in natural habitats with those under significant human pressure reveals certain adaptations which help these animals to survive. These changes take place during development of individuals (acclimatization) and within the population as a whole (modification). Larvae of Anura characteristically regulate their numbers through the death of some animals (Severtsov & Surova, 1989). In natural habitats embryonic mortality is not less than 30% whereas in polluted areas of Ukraine it is up to 90% or more. This suggests that individuals with a more plastic development survive when environments become unfavourable. Selection for a wider mode of reaction (accumulation of hereditary variability, preadaptation) also takes place, in extreme conditions, where variability of life cycle characters (size of eggs, rate of reproduction, age of reaching maturity, longevity, etc.) permit survival in unstable environments (Ishchenko, 1980). The usual form this takes in anuran larvae is an increase in variability of size, terms of development and death rate. Amphibians in an early stage of development are characterized by a high death rate and low body mass; in their middle period of development, they have a high variability of body size; in the final stage of development, the death rate decreases, and body mass increases sharply. Larvae with retarded growth are depressed by larger larvae, and stimulate their growth. (Pikulik, 1977). In the final stages of development elimination of the smallest individuals take place. The average size and mass of amphibias in the most changed and polluted areas are increasing (Bugayeva, 1983; Vershynin, 1982; Vershynin, 1996; Gogoleva, 1985; Ivanova, 1982; Misiura, 1985; 1989; Mikheyev, 1993; Ushakov et al., 1981; Ushakov et al., 1982, etc.). This is probably connected with better survival of the big animals and changes of metabolic processes (Hazelwood, 1970). Big larvae with accelerated metamorphosis have advantages and their survival is the highest (liapkov, 1985). The process of metamorphosis is energetically advantageous when body size is big (Crum, 1981). Regardless of population density, metamorphosis is successfully completed in larger animals which also have a wider range of food and are more competitive. Rapid larval development in unstable environments is further preferable because the larvae are the most vulnerable of amphibian stages, and because such development leaves more time for growth before wintering. There are, however, some disadvantages: the biggest individuals have shorter lives than smaller ones; they have less chance to encounter favourable conditions and they are more conspicuous. Under human pressure the population-genetic structure and characters of morphology and physiology of the Anura also change. As their variability increases, some anomalies appear, so that some characters of amphibian biology in areas under human pressure differ from those in natural habitats. Particular characters (rate of growth and development, mortality, stability of individual development) could be used as indicators for monitoring environmental quality. There is very little published work on adaptations of amphibians to human pressure in Ukraine and this phenomenon needs further investigation.