Abstract: The distribution ratio of picric acid between organic and aqueous phases in the solvent extraction of alkali metal with DBC, 18C6 is determined and the effect of polyether equilibrium concentration and picric acid concentration of aqueous phases on the distribution ratio studied. The plots of the distribution ratio of K+, Rb+, Cs+ between organic and aqueous phases against equilibrium concentration of DBC-18C6 and picric acid give slope Values of approximatly 1. The polyether cation complex is found to be 1:1:1 in stoichio-metry. The extractability of complex cation-picrate ion pairs decreases in this sequence: K+>Rb+>.Cs+. The values of the equilibrium constants of the complex formation decreases as the sizes of the alkali metal cations increase.