Multivariate classification methods are important for the ivestigation of life, enviromenment and sosiety. The classification procedure referred to as the G-mode was epplied to isolate hydrochemical homogeneons taxons in space and compare them. Two geochemical tendencys predicted in forming of grounwater chemical composition of the Donbass region of direct and reverse hydrochemical zonaliti. The groundwater change chemical composition from HCO - 3 - Ca 2+ low salinity to Cl - - Na + higt salinity on first tendency and to HCO - 3 - Cl - - Na + low mineralized sodawater on second tendency. Origin of soda-water cause processes of evaporation and condensation of water in of СН-rich gas fhase.
