Compared with the intrinsic ZnO-NWs, the ZnO-ZnS nano-heterostructure material formed by modifying ZnS on ZnO surface shows significant improvement in sensing performance to 5 ppm H2S gas at the working temperatures of 100-400 °C, especially in the low temperature range. Display omitted This paper reports a high-performance H2S gas sensing material that is made of ZnO nanowires (NWs) modified by an optimal amount of ZnS to form nano-heterojunctions. Compared with the intrinsic ZnO-NWs, the three differently modified nano-heterostructure material ZnO-ZnS-x (x = 5, 10, 15) shows significant improvement in sensing performance to H2S at the working temperatures of 100−400 °C, especially in the low temperature range (<300 °C). The chemiresistive sensor with ZnO-ZnS-10 sensing-material exhibits the largest response signal to H2S among all the other ZnO-ZnS-x (x = 5, 10, 15, 20) sensors. Its response signal to 5 ppm H2S at 150 °C is about 2.7 times to that of the ZnO-NWs sensor. Besides, the ZnO-ZnS-10 sensor also features satisfactory selectivity and repeatability at 150 °C. With the technical advantage attributed to the reduction of the redesigned band gap at the interface between ZnO and ZnS, the ZnO-ZnS heterostructure sensor rather than the traditional ZnO-NWs sensor can be used for high-sensitivity application at low working temperature.