ABSTRACT Sr2Bi4Ti5O18 (SBTi) and Sr-deficient SBTi thin films were deposited on Pt/Ti/SiO2/Si(100) substrates using a sol-gel method. Structure, morphology and electric properties were investigated systematically. These films were random-oriented and were composed of rod-like grains. The remanent polarization (2P r ) and coercive field (Ec) of SBTi films were 24 μC/cm2 and 68 kV/cm, respectively. This value of 2P r was much higher than the reported value of SBTi prepared by pulse laser deposition. The compounds with Sr-deficient and Bi-excess composition showed a very large remanent polarization of 35.5 μC/cm2. More importantly, both films showed high fatigue resistance against continuous switching up to 3 × 1010 cycles and excellent charge-retaining ability up to 3 × 104 s.