In this paper, we describe the conformational stability due to the local structural change of tetraethylammonium ion (abbreviated as Et₄N⁺) in water and alcohols. Our results indicated that the conformational stability of Et₄N⁺ has a close relation to the solvation of aqueous tetraalkylammonium salt (R₄NX) solutions. Furthermore, we discussed the relationship between the thermodynamic properties and microscopic information. We showed that the hydrophobic interactions and hydration are affected by the enthalpy and entropy differences of the Et₄N⁺ conformers in aqueous Et₄NX solutions, where the thermodynamic parameters of the conformers may be useful for explaining the changes.