ABSTRACT: In the central part of the Tisovec karst (Slovenské Rudohorie Mts.) in the Furmanec valley occurs two big karstic springs (Periodická vyvieračka and Teplica). These springs, dewatering the Wetterstein limestones and dolomites and Dachstein and Tisovec limestones of Silica nappe, exceed 20 l.s-1 and are exploited as drinking water source for Tisovec town. The recharge area of the Teplica spring is Suché Doly area. Periodická vyvieračka spring has not defined recharge area yet. Both springs are bound to the equal rock environment what offer the possibility for comparison of these springs. In both springs were measured dD, d18O, d34SSO4, d18OSO4 and T. Groundwaters are meteoric in origin, young. (< 5 - 10 years), isotope composition of sulphate sulphur is very near to the "background" sulphur similar to precipitation sulphur.