0.95 (Na0.5Bi0.5)TiO3-0.05 BaTiO3 +1 wt% Bi2O3 (NBT-BT3) ceramic is used as target to deposit the NBT-BT3 thin films. The excess 1wt% Bi2O3 is used to compensate the vaporization of Bi2O3 during the sintering and annealing processes. NBT-BT3 thin films are successfully deposited using radio frequency (RF) magnetron sputter method and crystallized subsequently using a conventional furnace annealing (CFA) process. The annealed process is conducted in air and in oxygen atmosphere at temperatures ranging from 600-800 degrees C for 60 min. As compared with the as-deposited NBT-BT3 thin films, the CFA-treated process has improved the grain growth and crystallization. We will show that the annealing atmosphere is the more important parameter to influence the grain growth and crystallization of NBT-BT3 thin films than the annealing temperature. The influences of CFA-treated temperature and atmosphere on the electrical characteristics of NBT-BT3 thin films, including the polarization characteristics (Pr, Ps, and Ec values), the capacitance-voltage (C-V) curves, and the leakage current density-electric field (J-E) curves, are also investigated in this study.