Blue development and blue economy are relatively new terms, although blue economy has been developing for centuries. Its potential on European, Croatian or regional level is huge. New researches point out that the Blue Economy impact will double in next ten years. Although present in theory since 1990ties, blue economy in last few years as a part of the answer on the global challenges, has been followed by the aspects of Green Development, Green Economy Green Growth as synonyms for desirable and necessary transition towards sustainability. The definition of Green Economy in perspective of long-term sustainability, environment protection and reduced use of natural resources is defined as well. Recognizing the importance of blue-green economy for the Primorje-Gorski Kotar County (PGKC) development, the authors describe the potentials and possibilities for development of the region, as well as analyse natural and other preconditions and point out the reached level of blue-green economy innovative sectors. The purpose of this research is to explain the importance of coastal area as a basic determinant for the blue-green economy as well as to analyze the development level of the blue-green economy in European Union, Croatia and PGKC. This paper determined the spatial, geographical, technical-technological and economical potential of PGKC, defined the regional advantages, peculiarities and limits of the blue-green economy implementation in PGKC and set the recommendations for the balanced development and maximal use of extensive regional potential.