Ferroelectric bismuth vanadate（B2VO5.5） thin films were successfully fabricated on n-type Si (100) substrate by sol-gel method. The microstructures of the films were investigated by X-ray diffraction and atomic force microscopy. The results indicated that B2VO5.5 thin films show a good match with the n-Si substrate and a high c-axis preferred orientation with a uniform grain distribution. The investigation on the electrical properties of B2VO5.5 thin films indicated that B2VO5.5 thin films show good capacitance-voltage characteristics, and the memory window was larger than 0.4 V with the gate voltage ±4 V. The leakage current density was about 5×10-8 Acm-2 when the applied voltage was 3.2 V. The dielectric constant and dielectric loss measured at 1 kHz were 95 and 0.22 respectively. All the results indicate that Bi2VO5.5 thin films have potential applications in ferroelectric memory devices.