The paper reports the preparation and gas sensing characteristic of ZnSnO3. The perovskite structure ZnSnO3 was prepared by hydrothermal process directly. Its crystal structure and ceramic microstructure were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Its grain size is about 500 nm, and homogeneous as well as monodispersive in shape. Furthermore, the gas sensing properties of the materials were tested in static state. It is found that the sensors have good sensitivity and selectivity to H2S. (c) 2006 Elsevier Ltd. All rights reserved.