Zn 2 SnO 4 three-dimensional (3D) flowerlike hierarchical nanostructures have been successfully synthesized via a simple one-step hydrothermal method. Field emission scanning electron microscopic (SEM) and transmission electron microscopic (TEM) results reveal that the Zn 2 SnO 4 flowerlike structures are assembled with nanorods. To demonstrate the potential applications, gas sensor is fabricated based on the as-synthesized hierarchical Zn 2 SnO 4 . Gas sensing test results show that the hierarchical Zn 2 SnO 4 sensor exhibits significantly better sensing properties compared with the compact Zn 2 SnO 4 structures. The enhancement of sensing performance is attributed to the unique 3D hierarchical nanostructures, the increased contact surface area between Zn 2 SnO 4 and target gases, and greater number of surface active sites on the surface of as-prepared gas-sensing material. The as-prepared Zn 2 SnO 4 are significant for further exploitation of the potential applications in the future.