The form factors in the leptonic three-body decays of K-meson are studied in terms of the dispersion theoretic techniques developed by Goldberger and Treiman. Assuming that the Kπ-resonance has a dominant contribution to the dispersion integral, we can show that the consequences of the partially conserved current hypothesis studied by Bernstein and Weinberg follow from the theory under the weaker conditions on the high energy behavior of the divergence of the current.