The radius of gyration, Rg, and the hydrodynamic radius, Rh, are the main experimental parameters that characterize the size of linear and branched macromolecules. In the case of dendrimers in solution, the ratio Rg/Rh, depending on the global conformation, varies from 1 (for a Gaussian soft sphere) to 3 / 5 (for a hard sphere). However, for high-generation dendrimers, this ratio may be less than the limiting value for a hard sphere. To understand the reasons of the low Rg/Rh value (