Abstract: BiFeO₃ film and 10 % La A site substituted BiFeO₃ films were prepared on LaNiO₃ bottom electrode by sol-gel process.Dielectric, ferroelectric and leakage conduction properties were studied.The study of ferroelectricity showed that it was substantially enhanced,since the remnant polarization increased to 2.20 μC/cm² from the original 1.67 μC/cm² through La substitution.While the study on dielectric property showed that La substitution enhanced the dielectric property.The dielectric loss on low frequency increased and decreased on high frequency,respectively.Moreover,leakage current was reduced through La substitution.