Effect of counterion on properties of amphiphiles was investigated concerning aqueous solubility, micellization temperature, critical micelle concentration(cmc) and micelle aggregation number of amphiphiles, where the attention was directed to divalent cationic counterions whose electric charges are concentrated, diffuse, and separate ones. The separation was made by a methylene chain. Ionic amphiphiles with fluorocarbon as counterion were found to have quite different properties from those of conventional amphiphiles. As for the separate charge, the extent of charge separation was minutely examined on solid and solution properties The solid state with counterion of diffuse or separate charge is less stable energetically and has higher aqueous solubility. The difference in cmc value among the three types of counterions is relatively small when the charge separation is small, but a large charge separation gives rise to a marked decrease in cmc value, suggesting that the methylene chain of separate charge folds and penetrates the inner hydrophobic part of the micelle. Examination on the conventional “Krafft point” from changes of solubility and cmc with temperature lead to the new term, “micelle temperature range (MTR) or micellization temperature (MT)”. Effect of pressure on micellization was also studied as for tetradecane-1-sulfonates with divalent cation of separate electric charge, the separation being varied, and the volume change of the micellization was evaluated, from which the micelle structure could be deduced.