The article deals with qualitative and quantitative NMR analysis of water glass for assessing capability of Tesla BS 587 A and Bruker spectrometers and for comparison of water glass samples of various densities. The analyses on the Bruker device give a more detailed information on present structures. The samples include trimers, tetramers, heptamers, and octamers, pentacyclic, tricyclic and bridged. Dimers, monomers and colloid phase are present to a lesser extent. With increasing density, the hexamer and trimer contents increase, whereas the cyclic tetramer and and colloid phase contents decrease. In higher-density water glass solutions, which slowly gel and crosslink, more structure motifs are present.