The SOFC interconnect materials La 0.75 Sr 0.25 Cr 1−x O 3−δ (x = 0-0.04) were prepared using an auto-ignition process. The influences of Cr deficiency on their sintering, thermal expansion and electrical properties were investigated. All the samples were pure perovskite phase after sintering at 1400 • C for 4 h. The cell volume of La 0.75 Sr 0.25 Cr 1−x O 3−δ decreased with increasing Cr deficient content. The relative density of the sintered bulk samples increased from 93.2% (x = 0) to a maximum value of 94.7% (x = 0.02) and then decreased to 87.7% (x = 0.04). The thermal expansion coefficients of the sintered bulk samples were in the range of 10.60-10.98 × 10 −6 K −1 (30-1000 • C), which are compatible with that of YSZ. Among the investigated samples, the sample with 0.02 Cr deficiency had a maximum conductivity of 40.4 Scm −1 and the lowest Seebeck coefficient of 154.8 μVK −1 at 850 • C in pure He. The experimental results indicate that La 0.75 Sr 0.25 Cr 0.98 O 3−δ has the best properties and is much suitable for SOFC interconnect material application.