The Chemical compound assessment based on hydrochemical data of more than 800 water Karelian objects and the surface waters basic chemical parameters correlations is presented. The surface water geochemical classification with its theoretical ground based on the basic chemical transactions was obtained during research and is given here. Alkalinity pH and huminity were chosen as the main classification parameters. The water objects distribution by huminity and alkalinity classes was obtained and 14 basic geochemical classes were picked out. The distributions of total Fe, total P, CO₂, and pH by evolved geochemical classes and their theoretical grounds are also presented in the paper.