Mixed matrix membranes (MMM) possess very promising properties that have remarkably surpassed that of polymeric and inorganic membranes. LSCF which is often used in preparation of cathode materials and solid electrolyte materials has been demonstrated to have good conductivity in a water solution. So it is introduced in the preparation of La0.6Sr0.4Co0.2Fe0.8O3/polyethersulfone (LSCF/PES) mixed matrix membrane to improve the rejection of inorganic salts and the conducting MMMs were prepared via the phase inversion method in this work. The LSCF nanoparticles were introduced in the membrane pores of the PES microporous membrane. The content of PES and LSCF were changed to improve the membrane performance. When the PES concentration is 16 wt.% and the LSCF weight ratio of the polymer is 20%, the membrane flux is 90.4 L.h(-1).m(-2), and the rejection of MgCl2 is 25.8% at 0.3 MPa and 20 degrees C. The membrane performance is greatly affected by the concentration of LSCF and aggregation of the nanoparticles. (C) 2014 Elsevier B.V. All rights reserved.