The influence of ambient humidity on the gas-sensing characteristics of metal oxide semiconductors has been one of the greatest obstacles for gas-sensing applications. In this paper, the pure WO 3 and CeO 2 -modified WO 3 nanocubes were prepared by a simple hydrothermal method, and their gas-sensing characteristics in dry and humid atmospheres were investigated. The results show that CeO 2 /WO 3 demonstrated excellent gas-sensing properties toward H 2 S with high sensitivity and high selectivity at 115 °C. Noteworthy, the humidity independence of the CeO 2 /WO 3 increased compared to the WO 3 . The response retentions over the whole humidity range of the CeO 2 /WO 3 -6 and CeO 2 /WO 3 -15 sensors were 70.3, and 76%, respectively, which were much higher than the WO 3 sensor (17.9%). The gas-sensing mechanism of CeO 2 -modified WO 3 is discussed based on the gas sensitivity properties. The obtained results provide a promising route to enhance the anti-humidity properties of metal oxide semiconductor gas sensors.