Hierarchical α-Fe₂O₃/SnO₂composites were synthesized by a low-cost and environmentally friendly hydrothermal strategy. The structure and morphology of composites were investigated by X-ray diffraction (XRD), field-emission electron scanning microscopy (FESEM), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). The results revealed that the α-Fe₂O₃/SnO₂nanorods grew epitaxially on the surface of SnO₂nanosheets. The diameter and length of the α-Fe₂O₃/SnO₂nanorods were about 10 and 80 nm, respectively, and the thickness of the SnO₂nanosheets was about 15 nm. The acetone sensing properties of the pure SnO₂and α-Fe₂O₃/SnO₂composites were tested. The results indicated that such hierarchical α-Fe₂O₃/SnO₂nanostructures exhibited an enhanced acetone sensing properties compared with the primary SnO₂nanostructures. For example, at an acetone concentration of 100 ppm, the response of the α-Fe₂O₃/SnO₂composites was about 17, which was about 2.5 times higher than that of the primary SnO₂nanostructures. The response time of the sensor to 60 ppm acetone was shorter than 3 s at the operating temperature of 250 °C.