In this review it is reported about the research on the structure of intermolecular water cyclic associates (clusters) with general formula (Н2О)n and their charged ionic clusters [(Н2О)n]+ and [(Н2О)n]- by means of computer modeling and spectroscopy methods as 1Н-NMR, IR-spectroscopy, DNES, EXAFS-spectroscopy, X-Ray and neurons diffraction. The computer calculation of polyhedral nanoclusters (Н2О)n, where n = 3–20 are carried out. Based on this data the main structural mathematical models describing water structure (quasicrystalline, continious, fractal, fractal-clathrate) have been examined and some important physical characteristics were obtained. The average energy of hydrogen bonding (DEH…O) between Н2О molecules in the process of cluster formation was measured by the DNES method compiles –0,1067±0,0011 eV. It was also shown that water clusters formed from 2H2О were more stable, than those ones from Н2О due to isotopic effects of deuterium.