The prerequisite for the development of a strategic environmental assessment (SEA) is the problem of accumulation related to the environment. From this point of view, the measures and methods of countering threats of a planetary scale are analyzed: global warming and climate change; water pollution and ocean acidification; loss of biodiversity. SEA is considered as a tool for balanced development of the territory, as a tool for verifying management and planning decisions, with the help of which it is possible to reveal risks and alternatives in the process of their implementation, to convey conflict situations regarding the use of the territory. The development of the SEA is interpreted as one of the key tools for the post-war reconstruction of Ukraine. The conditions for developing and ensuring the transparency of the SEO of urban planning documentation in spatial planning, it’s content, legislative support for this process and the degree of its European integration are highlighted. The purpose of the study is to show how the procedure of strategic environmental assessment allows optimizing management and planning decisions regarding the development of territories of territorial communities in the process of spatial planning. The legal aspects of SEA regarding general plans of settlements, complex plans for the development of the territory, zoning plans and detailed plans, stages of integration of SEA in urban planning documentation are analyzed. It is proposed to highlight individual stages of the SEO development process. For this, a graphic research method is used. The expediency of implementing into domestic practice the positive foreign experience of implementing SEO, in particular, regarding: construction projects, for example the formulation of projects and evaluation of green construction, sanitary and other facilities, determination of the ecological life cycle of construction products; determining the effectiveness of SEO by whether its benefits are worth it, presenting it through the prism of knowledge and learning, as well as contextual, pluralistic, substantive, normative, and trans active dimensions; delivery of online registers of all SEO documents; promoting an open and proactive attitude to SEO among planners through the SEO Forum. The proposal to include indicators of the ecological capacity of the territory in the SEO (in the existing state and according to the project): coefficients of ecological stability, ecological danger and anthropogenic load are argued. For this, the tabular and normative method of calculation is used. The scientific and practical significance of the article lies in the introduction of the basic indicators of the ecological capacity of the territory (before and after the project of the Comprehensive Development Plan of the territory of the territorial community) into the SEO, which allows to compare the existing and project state of the territory and the environment in terms of the coefficients of ecological stability, ecological danger and anthropogenic load. The ability of the SEO to comprehensively analyze the possible impact of the planned activity on the environment is demonstrated. Keywords: SEO, spatial planning, urban planning documentation, report, territorial community, public discussion, ecological capacity of the territory.