Good oxygen permeability and stability of oxygen transport membrane are highly necessary for practical applications. Herein, through different theories, the oxygen transport limitation step through the Ruddlesden-Popper (Pr0.9La0.1)(1.9)Ni0.74Cu0.21Ga0.05O4+delta ((PL)(1.9)NCG) membrane was demonstrated firstly, which suggest surface modification can be an effective approach to improve the oxygen separation performance. After coating, various influences of different side surface modification on permeability and phase stability were observed. The sweep-side coated membrane exhibits largely enhanced permeation fluxes than feed-side coated membrane, and the feed-side coated membrane shows better phase stability under the same conditions (these results reveal that the sweep side is the permeability limitation side and the feed is the phase stability limitation side). The both side coated membrane combines abovementioned advantages which shows 57% enhanced and stable oxygen permeation flux at 800 degrees C. The observed various modification effects on the permeation performance are discussed based on the surface exchange properties and the mechanism of the oxygen transporting membrane in detail.