The monograph summarizes the work related to the introduction of the European Reference Coordinate System (EUREF) in Bulgaria. The foundations, prerequisites, essence and necessity of the system are set out, as well as its connection with the development of global navigation satellite systems. The seismotectonic conditions on the territory of Bulgaria, the construction of the EUREF network, research and application of the system in Bulgaria, as well as the regulatory documents for this are presented. The Single European Height System and its introduction in Bulgaria together with the European Combined Network are also presented. The results of other activities related to EUREF, as well as its introduction in neighboring countries are also summarized. The monograph is intended for specialists in geodesy, cartography, cadastre, photogrammetry and other Earth sciences, in navigation, transport and many other areas of science and business. It was published with the support of the National Council "Scientific Research" under the Ministry of Education and Science.