An oxygen transport ceramic membrane was prepared with La0.6Sr0.4TixFe1-xO3-delta (x = 0.2 and 0.3) oxides which was synthesized by polymerized complex method. In order to investigate the effects of Ti Substitutions Into lanthanum-strontium ferrites, material property, thermal expansion coefficient, oxygen permeation, electrical conductivity and phase stability were examined according to Ti contents. The thermal expansion coefficients of LSTF6428 and LSTF6437 were 25.76 x 10(-6) K-1 and 21.32 x 10(-6) K-1 in the temperature range of 973-1273 K, respectively. The oxygen permeation fluxes through a disk type dense membrane of LSTF6428 and LSTF6437 with 1.6 mm thickness increased exponentially with increasing temperature and were 0.17 mL min(-1) cm(-2) and 0.13 mL min(-1) cm(-2) with P-h = 0.21 atm (O-2 rich side) and P-1 = 10(-5) atm (lean side) at 1223 K, respectively. In the result of phase stability test with various conditions such as He, H-2/N-2 and CO2 atmosphere, La0.6Sr0.4Ti0.3Fe0.7O3-delta was confirmed to be more stable than La0.6Sr0.4Ti0.2Fe0.8O3-delta through XRD and SEM analysis.