As a result of human activity in the environment, there is a large amount of toxic substances that affect all elements of ecosystems: soil, plants and animal organisms and human. Particularly significant environmental changes are characteristic forUkraine, where powerful enterprises of the chemical, metallurgical, energy and other industries with outdated technologies are concentrated. G.M. Ilkun identified a special type of pollution - Ukrainian, which is characterized by high concentration of toxic substances in the environment. In these conditions among the most promising fruit cultures ofUkraineare representatives of the genus peach. Despite significant advances in the introduction and acclimatization of the peach, its gene pool should be constantly replenished by varieties of the new generation, characterized by increased adaptation to stress factors of the environment and significantly higher productivity of species. Especially important is a receipt of sorts to peach (Persica of vulgaris of Mill.), which have high taste qualities, are resistant to local conditions and mycotic diseases. Among the important factors that indicate the level of adaptation of organisms to new environmental conditions are indicators of the functioning of antioxidant enzyme systems, in particular peroxidase. An important role in the reaction of plants tolerance to environmental conditions is played by the antioxidant system. One of constituents of this system there is peroxidase, the activity of which varies depending on the tension of ecological factors. Based on the above, the main purpose of research is to study the peroxidase activity of introduced taxa genus Persica Mill., as an indicator of the stability of sorts for the further implementation of the development of modern systems horticulture and landscaping industrial city. Conducting comparison of analysis of the activity of oxidative-reducing enzymes of both in hybrid forms and in the pure line. According to the obtained indexes to set the most perspective forms of peaches for the use in the conditions of steppe Dnieper as a technically-decorative culture. Investigated plant samples (one-year-old shoots) were selected on the territory Botanical Garden of the Oles Honchar Dnipro National University. The objects of research were hybridogenic forms of stone fruit (peach and almond species) of the breeding Nikitsky Botanical Garden, growing on collectable area of the Botanical Garden of the Oles Honchar Dnipro National University, from which 12 forms were selected. Biometric indices and activity of plant peroxidase were measured according to generally accepted methods. As a result of the experiment, it was found that there are significant differences in the experimental plants between the activity of peroxidase in different hybrids, but the general tendency is maintained: the activity of this enzyme in experimental plants is higher than in the control. On our opinion plants react on the unfavorable factors of environment increasing of activity of peroxidase. For each plant species, the value of activity of peroxidase was specific due to heredity, which for a long time was formed in the specific ecological and geographical conditions of those regions where these species were formed. It is noted that the level of activity of peroxidase in autumn does not go back to corresponding at the beginning of spring. This indicates a slowdown in the transition of plants to a state of relative calm. It can also confirm visual observation (resetting leaves after frost occurs in the absence of autumn color). The conducted studies of the activity of peroxidase in the leaves of the studied hybrid forms varied over the course of the vegetation period. Thus, as a result of our studies, it has been found that the plants of the studied hybrid forms F2 are characterized by a wide range of changes in the activity of peroxidase. It can be assumed that this phenomenon is associated with the formation of new taxa due to hybridization in F2, when hybrid forms in their qualities may differ significantly from each other due to splitting. Therefore, the activity of peroxidase can be various, both above and below the corresponding indicators in the etalon. In accordance with this among the obtained hybrids is forms like a resistant to the conditions of introduction and not enough resistant. This makes it possible to recommend varieties with high resistance for a wider introduction development of modern systems horticulture and landscaping industrial city, or as a breeding material for the creation of fruit crops.