The electric conductances of dilute solutions of alkali chlorides (LiCi, NaCl, KCl, RbCl, CsCl) in a series of acetone-water and formic acid-water mixtures were determined respectively at $^30{circ}C$. The results of the conductances of alkali chlorides in acetone-water mixtures were analysed by the Debye-Huckel-Onsager equation and the variations of limiting equivalent conductances with the compositions of acetone-water mixtures were explained in terms of selective solvation of electrolytes. The conductances of dilute solutions of alkali chlorides in formic acid-water could not be analysed because of the strong ionic atmosphere of solvent itself.