采用化学共沉淀法制得不同掺杂量的SnO2-WO3 粉体，探讨了掺杂量、热处理温度、元件工作温度与WO3气敏性能的关系。研究发现：SnO2 的添加抑制了WO3 晶粒的生长，提高了其气体灵敏度。其中以0.5%（质量分数）的掺杂量为最佳，可进行H2S 气体的选择性检测。关键词:三氧化钨；气体传感器；硫化氢；化学共沉淀法；半导体Abstract: The powder of xwt.% SnO2-WO3 is prepared by coprecipitation. The effects of SnO2 content, calcining temperature and sensors’ operation temperature on the sensitivity are investigated. The results show that sensitivity rises and WO3 mean grain size become smaller when SnO2 added, and that the sensitivity to H2S can be acquired when x = 0.5.Key words: WO3; gas sensors; H2S; chemical copercipitation; semicoducto