The selective distribution of alkaline earth metal ions between carbon tetrachloride and aqueous sodium perchlorate solutions has been investigated by adding chelate forming llgand (thenoyltrifluoroacetone, TTA) and adduct forming llgand (trloctylphosohlne oxide, TOPO) of high concentrations (0.1 M) at 298 K. The separation of alkaline earth metal ions Is explained in terms of their solvent extraction with hydrogen ion in aqueous solutions. The selectivity series, Mg2 +> Ca2 +> Sr2+> Ba2+was established by the solvent extraction method. On the other hand, the selectivity series by the ion-exchange method has been known as Ba2+> Sr2+> Ca2+> Mg2+using crystalline dihydrogen tetratitanate hydrate fibers, H2Ti4O9-nH2O, and aqueous solutions at 298 K. The difference in the two selectivity series is interpreted by the solvation (former) and hydration (latter) effects of metal ions. The values of the separation factors for alkaline earth metal ions given by the combination of the two methods is extremely high, and all probable pairs of these metal Ions can completely be separated.