Ovules of Aesculus glabra Willd. were used as experimental material. Concentrations of K, Ca, Na, Mg, Fe, Mn, Zn and Cu were determined quantitatively in the central vacuole sap and in the developing embryo. Generally concentrations of all investigated elements in the central vacuole sap and in the embryo changed during embryogenesis. Total concentration of K + Ca, and Mg + Fe + Mn + Zn + Cu in the sap increased during the beginning of embryo differentiation and subsequently decreased markedly during its further development. A similar change in total concentration of these elements was found in the developing embryo. Concentrations of elements in the embryo (except Mn) were much higher in the embryo than in the central vacuole sap. It is suggested that the elements occurring in the sap were selectively taken up and accumulated in the developing embryo.