|| Sixty-five samples of mineral waters (mainly
above 25℃) from western Japan were analyzed for
their Li, Na, K, Mg, Ca, Al, Fe, and Cl contents. The determination of Li was carried out by argentimetric titration of LiCI after the removal of other components by the cation exchange chromatography. A significant correlation between Li and Na concentrations is demonstrated in most samples, in which the contamination of sea water is hardly conceivable. This strong correlation of Li and Na can plausibly be explained assuming that these components have dissolved into the ascending mineral waters from the country rocks having fairly uniform Li to Na ratios. In this connection it is noted that western Japan is characteristic of the vast outcrops of granodioritic or granitic rocks.