The article provides information on the location and biometric parameters of 192 agelong trees growing in the landscape park «Nataliivskyi» (Kharkiv region). The results of continuous cencus on a 0.25 ha sample area in age-specific pine stand are presented. The plantations of agelong pines cover 17.8 hectares, or 51.5% of proved area. The average trunk diameter of Pinus sylvestris L. is 45.2 cm. The number of trees per hectare is 244 pcs. There were also 2 Ulmus laevis Pall. trees and one Pyrus communis L. tree and four bushes: Crataegus monogyna Jacq. There is no undergrowth or young growth on the plantation. No invasive species have been found. The most valuable trees in the park are the agelong Quercus robur L. Biometric indicators have been identified for most of the old oak trees. For the majority of agelong oaks species biometric indicators were determined. The trunk circumference of other agelong tree species was also measured to obtain the trunk diameter. The location of agelong trees was recorded on the park plan. The data from the park’s 1997 and 2018 studies were used during examination and analysis of results. It was found that the number of Picea abies and Picea pungens ‘Glauca’ plants in the park has been significantly decreased due to the drought and the attack of engraver beetle. A significant number of dead trees were found in the park, which indicates the need for sanitary felling to remove them. It was found that in general, the condition of the park’s ageold trees is satisfactory. However there are trees with hollows in their trunks and with dry branches. Quercus robur L. with the largest trunk diameter of 207 cm has a hollow. Once it was closed using an outdated method – cement mortar. This technology is not currently used to preserve ageold hollow trees. Modern technologies of caring for such trees ensure their long life. The individual care of agelong trees by arborists is an important issue. Unfortunately due to the lack of funding for the park’s maintenance it’s impossible to use modern technology and employ professional arborists. The emergence of self-seeding of indigenous and introduced species within the crown projection of agelong Quercus robur, as well as shading of their lower branches by these trees is another threat to old trees. It is necessary to remove young self-sowing plants within the crown projection. As a result of the study, it was established that there are 19 species and cultivars of agelong trees in Nataliivskyi Park. Some of them are represented by only 1-2 plants. Therefore, there is a threat that they may disappear from the plantations. In order to preserve the taxonomic composition of the park, it is necessary to plant some more trees of the exact species that were planted during park creation. Nataliivskyi Park is an important nature conservation institution. The data of conducted research can be used in the future to monitor the health of agelong trees.

Key words: an ancient park-monument of landscape art, species composition of ageold trees, trunk diameter, plantings.