The influence of interfacial tension, density difference and viscosities of immiscible liquid phases on the stationary phase retention in a coil planet centrifuge has been studied. Two-phase liquid systems containing organic solvent (n-decane), extracting reagent (di-2-ethylhexylphosphoric acid), water, surfactant (sodium salt of dodecylbenzenesulphonic acid) and mineral salt (ammonium sulphate) have been considered. Varying concentrations of the system constituents allows selectively changing the interfacial tension, density difference or viscosity, all other conditions remaining the same. It has been shown that these parameters, especially interfacial tension, strongly affect the stationary phase retention. The data obtained are in good agreement with proposed theoretical models.