We investigated the influence of the growth temperature, O₂ flow, molar ratio between Ga₂O₃ powder and graphite powder on the structure and morphology of the films grown on the c-plane sapphire (0001) substrates by a carbothermal reduction method. Experimental results for the heteroepitaxial growth of β-Ga₂O₃ illustrate that β-Ga₂O₃ growth by the carbothermal reduction method can be controlled. The optimal result was obtained at a growth temperature of 1050 °C. The fastest growth rate of β-Ga₂O₃ films was produced when the O₂ flow was 20 sccm. To guarantee that β-Ga₂O₃ films with both high-quality crystal and morphology properties, the ideal molar ratio between graphite powder and Ga₂O₃ powder should be set at 10 : 1.