$^{226}Ra$ in groundwater could be analyzed by various methods. LSC (liquid scintillation counter) is used to measure its activity of Ba co-precipitates with Hisafe III scintillation cocktail solution. Counting efficiency was obtained using NIST
$^{226}Ra$ standard solution in triplicate and calculated
$^{226}Ra$ concentration using the efficiency values.
$^{226}Ra$ values of 19 groundwaters having Gross-
${\alpha}$ concentrations of more than 5 pCi/L ranged from ND (
${\leq}$ 0.1 pCi/L) to 1.18 pCi/L. Geologic settings of the 19 areas are composed of granitic rocks of Pre-Cambrian and Jurassic and Cretaceous, gneiss (schist) of Pre-Cambrian, and volcanic rocks of Cretaceous. No relationship was shown among
$^{226}Ra$ a concentrations and in-situ water quality data, and Gross-
${\alpha}$, uranium, radon concentrations.
Keywords: $^{226}Ra$;LSC;Gross-${\alpha}$;Uranium;Geologic setting;