The first oxygen permeation data for a dense hollow fiber membrane based on a K2NiF4-type oxide are reported. The U-shaped (Pr0.9La0.1)(2)(Ni0.74Cu0.21Ga0.05)O4+delta (PLNCG) hollow fiber membranes were prepared by a phase inversion spinning process. The dependences of the oxygen permeation on the feed air flow rate, sweep helium flow rate, oxygen partial pressure On the shell side, and operating temperature were experimentally investigated The effects of the bulk diffusion and the surface exchange on the oxygen permeation flux through the U-shaped PLNCG hollow fiber membranes are also discussed During around. 320 h of operation, a steady oxygen permeation flux of 1.0 mL/(min.cm(2)) was obtained at 975 degrees C under condition's of an air feed flow, rate of 180 mL/min and a helium sweep flow rate of 55 mL/min. XRD and SEM analyses Of the spent hollow fiber membrane showed the good stability of the U-shaped PLNCG hollow fiber membranes.