Objective – to investigate of the population density of box tree moth (Cydalima perspectalis (Walker, 1859)) on Buxus sempervirens L. on the territory of M.M. Gryshko National Botanical Garden of the NAS of Ukraine and determine the effect of the use biological preparations against this pest. Material and methods. The object of the study was Cydalima perspectalis. Experimental work was carried out on the territory of M.M. Gryshko National Botanical Gar den of the NAS of Ukraine. For evaluate the degree of damage to plants by Cydalima perspectalis, an original scale has been applied. The research was carried out during 2017—2018 with the use of biological pesticides: Lepidocide (100 ml/ 10 L of water), Bitoksibacillin (100 ml/10 L of water), Aktofit (100 ml/ 10 L of water). The standard version was taken by Decis (deltametrin) (1 g/10 L of water) and Mospilan (acetamiprid) (3 g/10 L of water). The prevalence and density of caterpillar populations, damage and effectiveness of the preparations were determined by generally accepted methods. Results. In 2016 it was discovered the mass invasion of plants of the box by the new invasive kind of pest Cydalima perspectalis in M.M. Gryshko National Botanical Garden of the NAS of Ukraine. It was investigated the cycle of development of these insects in Kyiv. The research of the effectiveness was carried out. It was developed an original scale for assessing the degree of damage to plants by Cydalima perspectalis. It was determined the effectiveness of biological pesticides and the best combination of its. It was proved expediency of the use of these drugs in the protection of plants of box tree from Cydalima perspectalis. Conclusions. It was established that the treatment of plants with biological preparations Lepidocide (100 ml/ 10 L of water), Bitoxibacillin (100 ml/10 L of water) in combination with Aktofit (100 ml/10 L of water) is effective in protecting against Cydalima perspectalis. Recommended use of these biological pesticides in the protection against box tree moth in botanical gardens and arboretums.