Abstract: The inherent errors and distorsions in the astrogeodetic network of Slovenia make it unsuitable for today's requirements which not only include national mapping and cadastral purposes, but also scientific and safety purposes such as earthquake prediction, crustal dynamics and land subsidence. Now with the advent of new technologies such as GPS, it is becoming of increasing importance that such accurate surveying measurements could be included into an existing coordinate frame without degrading the measurements itself. It is obvious that such control network must be realized in terms of a stable and consistent coordinate frame which is of a global nature. In order to implement such a modern threedimensional coordinate system, country should have all reference systems (height and horizontal datums) well defined and up-to-date. One of the prerequisites for that is also an accurate geoid-the reference surface for height determination, which requires also absolute gravimetry measurements, which were carried out in the frame of UNIGRACE project.