The $Sr_{0.7}Bi-{2.3}Nb_2O_9$(SBNO) thin films were deposited on Si substrate by RF magnetron sputtering method at $300^{circ}C$ of substrate temperature. And the SBNO thin films were annealed at $650{sim}800^{circ}C$ using RTA (rapid thermal annealing). The grain of SBNO thin films were increased with the increase of annealing temperature. The dielectric constant (100) of SBNO thin film was obtained by RTA above $750^{circ}C$. The voltage dependence of dielectric loss showed a value within 0.03 in voltage ranges of -5~+5 V. Also, the dielectric constant characteristics showed a stable value with the increase of frequency.