Abstract: A wealth of isotope date indicate the following: the groundwater recharge and renewal in the plain area in the southern part of the Heihe River basin are nonuniform and limited; the phreatic water is younger and renewed more rapidly than confined groundwater; the groundwater in the eastern area of the middle reaches is renewed more rapidly than in the western area; groundwater in the gobi zone in the front of the Qilian Mountains is renewed more rapidly than that in the fine soil plain; and groundwater near the riverbed is renewed more rapidly than that far from the riverbed. The above-mentioned characteristics are closely related to the surface runoff out of the mountains and the attribute of the recharge resource of groundwater. Therefore it is beneficial to groundwater resources sustainable utilization to make full use of the strong infiltration and groundwater regulating and storing functions of the gobi zone in the piedmont plain of the Qilian Mountains, combined with the groundwater renewal characteristics and surface water regulation.