Primary and derived parameters of common relevance of astronomy, geodesy, and geodynamics

Problem of selecting primary parameters has been discussed. Primaries should be defined uniquely, as well as, physically. Since no unique definition for semimajor axis exists, it should be replaced by the geoidal geopotential value W-0 or by the geopotential scale factor R(0) = GM/W-0, geocentric gravitational constant GM be also primary parameter. Current best estimates of some parameters are given numerically.