In this work, we reported a novel toluene sensor based onα-Fe₂O₃/SnO₂heterostructure nanowires arrays, which were synthesized via combining an ultrasonic spray pyrolysis (for the SnO₂nanowires arrays) method and the subsequent hydrothermal strategy (for theα-Fe₂O₃nanorod branches). Various techniques were employed for the characterization of the structure and morphology of the as-obtained products. The results revealed thatα-Fe₂O₃nanorod branches grew on SnO₂nanowire arrays with an average length of about 800 nm. As a proof-of-concept demonstration of the function, such novel heterostructure nanowires arrays were used as the sensing material for gas sensors. As expected, the heterostructure composites exhibited good sensing performances for toluene, superior to a single component (SnO₂nanowires arrays). For example, the response of theα-Fe₂O₃/SnO₂composites was up to 5 times higher than that of the primary SnO₂nanowire arrays at 90℃.