The article briefly describes the history of the Green Belt of Fennoscandia (GBF), a system of existing and planned specially protected areas (PAs) located along the state border (on both sides) between Russia and Finland, Russia and Norway, and presents some results of the 30-year research of natural complexes and unique natural objects located on its territory. The information on PAs of the GBF was updated and its boundaries were specified. Based on the analysis of the accumulated data, the authors assess the current state of the GBF and the prospects for its development, as well as indicate the objectives of further research. The authors emphasize that the GBF, as a system of interconnected protected areas, has now become not only a special phenomen on in the field of ecology, but also an important real system-forming unit of the future ecological framework of Northern Europe, and the concept of green belts should become one of the key elements of the state policy in the field of environmental protection.