In this study, heavy rare earth garnet Temperature Dependent Cation Distribution in Tb₂Bi₁Ga1Fe₄O₁₂ powders were fabricated by a sol-gel and vacuumannealing process. The crystal structure was found to be single-phase garnet with a space group of Ia3d. Thelattice constant a0 was determined to be 12.465 Å. From the analysis of the vibrating sample magnetometer(VSM) hysteresis loop at room temperature, the saturation magnetization and coercivity of the sample are 7.64emu/g and 229 Oe, respectively. The Néel temperature (TN) was determined to be 525 K. The Mössbauer spectrumof Temperature Dependent Cation Distribution in Tb₂Bi₁Ga1Fe₄O₁₂at room temperature consists of 2 sets of 6 Lorentzians, which is the pattern of singlephasegarnet. From the results of the Mössbauer spectrum at room temperature, the absorption area ratios ofFe ions on 24d and 16a sites are 74.7 % and 25.3 % (approximately 3:1), respectively. These results show thatall of the non-magnetic Ga atoms occupy the 16a site by a vacuum annealing process. Absorption area ratios ofFe ions are dependent not only on a sintering condition but also on the temperature of the sample. It can thenbe interpreted that the Ga ion distribution is dependent on the temperature of the sample. The Mössbauermeasurement was carried out in order to investigate the atomic migration in Temperature Dependent Cation Distribution in Tb₂Bi₁Ga1Fe₄O₁₂.