ENThe article analyses urban functional structure on the example of the Old Town of Vilnius. From the historic point of view, the urban functional structure as well as the priorities of functions have changed a number of times. The reasons for these changes were related to the economic and political background of the state and of the city. As the urban functions were changing, the urban areas were also rearranged. Green plantations and green areas are among the key components of the urban functional structure. The development of green urban territories has actually been very complicated: original forests, groves and clumps of trees were gradually replaced with gardens, parks, community gardens, etc. Their functions were changing alongside. In recent years, after the modification of political, economic and public systems of the Republic of Lithuania, the functional orientation of the city of Vilnius has also been rearranged and reformed. Therefore, during the current transitional period, it is very important to create a balanced layout of business and residential areas, service and recreational zones not only in terms of the overall city, but also of its individual parts. There is a need for an optimal and human-friendly system of green territories, as they affect the other, for example, residential, recreational, and even business functions. The green plantations and green areas located in the city perform specific and at the same time complex functions. We classified these functions as urban-ecological, urban, and recreational. Green plantations and green areas perform the said functions efficiently only provided there are appropriate conditions for their growth and development.The article addresses a very pressing problem - inconsistency and discrepancies in the terms and concepts used to refer green urban territories that are employed in the works on planning, management, etc. Another urgent issue is absence of classification of green urban territories or standardisation documents, which impedes the formation of the optimal system of green urban territories and their protection from construction. A survey of green territories in Vilnius proved that in ten years after the restoration of Independence, after having returned and established private ownership in the state, after having developed territorial planning, the country’s policy with respect to green territories in cities, towns and rural areas has not been developed yet.