The role of groundwater feeding of rivers was studied, it has been approved that, this process happen in period storm rainfall very weak, it is more intensive 3-5 days after rainfall and proceed gradually next droughty(rainless) days. The empirical relation formula has been proposed for estimation of the baseflow allotment on the feeding and water balance of rivers on based rational method and the capabilities of GIS techno­logy ­for the first time. The comparison of rivers’ baseflow datas (Kurmukh and Turyan) obtained by rational method and actual observational datas of hydrometric gaging stations shows that the difference between them is very little, or in most cases, there is not. Consequently, all these demonstrate to possibility of the rational method for estimation underground feeding and baseflow of rivers on any non-observation basin areas irrespective its geographical conditions.