Abstract: Gas sensors play an important role in modern science and technology; they are widely used in public safety, pollution monitoring, respiratory analysis, smart homes, etc. Their low cost, high sensitivity and ease of manufacture have prompted many researchers to conduct extensive research on gas sensors. In particular, metal oxide semiconductor（MOS） type gas sensors, which can detect more than 150 toxic and hazardous gases, have good gas-sensing properties for organic volatile gases（VOCs） such as ethanol（C₂H₅OH）, which is volatile and flammable and explosive in nature. This paper reviews the state-of-the-art MOS resistive ethanol sensors in the last year and details the sensing mechanism of the sensors for ethanol gas; it highlights the sensitive characteristics of different MOS-based sensors for ethanol and analyses the effects of, for example, metal doping, heterojunction composites and MOS hierarchical structures on the performance of ethanol sensors. The analysis shows that SnO₂ and ZnO-based sensors have the best sensing performance to ethanol, especially MOS sensors doped with metals and constructed heterojunction from different conductive types of semiconductors.