BiFeO3 thin films were spin-coated on conductive indium tin oxide (ITO)/glass substrates by a simple sol-gel possess annealed at 470-590°C. The crystal structure of as-prepared BiFeO3 thin films annealed at different temperature was determined to be rhombohedral of R3m space and free of secondary phases was also confirmed. Cross section scanning electron microscope (SEM) pictures revealed that the thickness of BiFeO3 thin film was about 320 nm. The double remanent polarization 2Pr of BiFeO3 thin film annealed at 500°C is 2.5 μC/cm2 without applied field at room temperature. Image of atomic force microscopy indicated that the root-mean-square surface roughness value of BiFeO3 thin film was 6.13 nm.