Phase equilibria in quinary Na, K//Cl, SO4, B4O7-H2O system at 25 degrees C were investigated by means of translation method. Five invariant points, 16 monovaraint curves, and 18 divariant fields have been determined in the system on quinary composition. A comprehensive phase equilibria diagram for the system was constructed on the basis of obtained data. The diagram was fragmented into divariant cocrystallization fields and trivariant volumes of two different solid phases and individual equilibrium solid phases, respectively. The comparison of obtained results with available experimental data was deliberated.