The scientific-research base of the Arboretum Mlyňany takes an important part in investigation and solving of the topical problems of woody plant and greenery in the urbanized and landscape environment. From among a wide range of results the most valuable are the following: ecoproduction of selected species of indigenous and exotic woody plants, dendrogeography of landscape wholes before the man’s intervention into them, dendrological and architectural evaluation of historical parks in Slovakia from the view of reconstruction, zoning of exotic woody plants and their applicability in greenery setting to settlement and landscape, principles for park forest creation, functional green spaces in industrial agglomerations and in surrounds of nuclear plants, greenery normatives and estimation of trees in settlements, diseases and pests of woody plants. Experimental works are directed towards: phytoncidic efficiency of woody plants, share of woody plants and green spaces in the air detoxication, in noise silencing, climate melioration, development and creation of leaf biomass from the point of view of their effects on the air quality, resistance of woody plants to salts, woody plants and urban soils in towns. The future period will be aimed at the study of actual problems of woody plants, and greenery in general, in the urbanized environment.