The project analyses determinants of productivity gaps between the average productivity levels of the EU-15 and a selection of most advanced Central East European Economies (such as Czech and Slovak Republic, Estonia, Hungary, Poland and Slovenia). The objective is the generation of a unique knowledge base on the various determinants of lower levels of economic development in accession countries. Determinants assessed comprise of three groups: patterns of domestic and international specialisation at the macro-level, technological sophistication of production at a mezzo level, and firm-specific determinants at the micro-level of individual enterprises field work. This newly generated body of comparative knowledge will be compiled with a view on an effective management of the accession process, and strategies.This paper summarises research results of WP4 subproject: Mapping the Technology Structure of Branch Plants and Technology Integration of CEECs. Each of the five country studies presented an overview (I. part) about economic development, changing conditions for, and results of FDI as a mechanism of productivity growth in Estonia, Poland, Slovakia, Slovenia, and in Hungary at a comparative way. The second part presents the descriptive analyses of the answers of FIEs (subsidiaries of foreign firms) on a two page structured questionnaire and first results of regression analysis to determine which factors are significant overall these subsidiaries in the five countries. We will focus on differences rather than similarities by summarising the main features of economic development and changing conditions, and of FDI-inflows by countries (I. part). The second part, based on fieldwork results, generating a large database on altogether of 458 foreign subsidiaries, will summarize the determinants of subsidiary’s autonomy, the role of parent firm in different business functions, market-orientation, and structural differences. We focus on the links to the magnitude of changes, what role the FDI had in productivity growth, sales-, exports-, technology, and quality improvement by structural differences in each country to understand the different results and prospects.