This study aims to advance the knowledge of the system of spatial planning instruments and of the Europeanization process, having as an object of study a country from Eastern Europe: Bulgaria. The actuality of the topic is justified by the fact that Bulgaria is one of the new EU member states and also by the need to understand how the national system of spatial planning is transformed and Europeanized as a result of this membership. Understanding and interpreting the changes in the planning system after the fall of the communist regime in 1989 and the country's preparation for EU-membership, followed by an analysis of the system of spatial planning instruments and its implementation in the process of Europeanization, shape out the two main successive lines of research, which define the main objectives of the study. The time scope of the study covers the period between 1989 and 2013, thus coinciding with the end of the first programming period for Bulgaria as an official member of the Union. The study follows the dynamics of the various dimensions of the system of spatial planning, with special focus on those periods when the Europeanization process has had the greatest impact in the transformation of the system of planning instruments, respectively – the strongest impact on the spatial instruments - and its implementation through new ones, in the context of the European spatial discourse or model. The analysis of the studied literature and documents, as well as the conducted interviews, show and argue that Bulgaria has made significant efforts in introducing new planning instruments, mostly related to regional development planning, but without any reformation and integration of the system of spatial planning. The implementation of the Integrated Plans at the local level and the National Spatial Development Concept as new spatial instruments - an expression of the coordination of the physical planning and the development of the territory, although within the legal framework of regional development - display the first attempts for integration of the planning system, discursive integration and transfer of the ideas of the European spatial model.