Metal oxide semiconductor gas sensor has attracted widely because of its high sensitivity, low manufacturing cost and simple measurement, which has great utilization potentiality in the aspect of the detection of toxic and harmful gases. Doping, as one of the most commonly used for modification method in the preparation process, has been paid lots of attention and researched wildly by domestic and international scholars. Therefore, the research progress of metal oxide semiconductor gas sensing materials is reviewed from the perspectives of doping, such as pure metal oxide, pure metal doping, rare earth element doping, composite metal oxide, metal oxide doping and so on. Furthermore, the problems and the developing tendency are summarized.