The results of the field and laboratory assessment of the drought tolerance of the representatives of the family Caprifoliaceae of the Nikitsky Botanical Garden collection are presented in the article. Specific features of the regulation of the water regime at the beginning of vegetation in optimal and extreme conditions of the growing season on the southern coast of the Crimea are described. Reversible and irreversible damages caused by hydrothermal stress were analyzed. The values of the parameters of the total water content in leaf tissue, water-deficit and waterholding capacity are indicated. For the least stable taxa the maximum values of the coefficients of variation of these parameters of the water regime are characteristic. At the same time a high level of potential drought resistance is characteristic for L. fragrantissima, L. henriу, L. maackii, L. nitida, L. pilеata, L. nitida ‘Elegant’ (род Lonicera), W. floribunda, W. × 'Van Houttei' W. 'Red Prince' (род Weigela) и A. × grandiflora (род Abelia) in which during hydrothermal stress increases the water-retention capacity and water-absorbent capacity of the leaf tissues, the water deficit does not reach the sublethal level, the total water content is reduced by no more than 10 % compared to the water content in the optimal period of vegetation
