Objective To analyze and sort the fleas in the plague foci of Spermophilus alaschanicus in the Ganning loess plateau for providing the epidemiological data on fleas for the control and prevention of plague. Methods The Methods of descriptive epidemiology was used for the integrated analysis of the composition of fleas based on the data sorted according to the Siphonaptera, Class Insecta, the Chinese Fauna. Results A total of 62 species of fleas (subspecies), which belonged to 26 genera and 7 families, were found in the plague foci of S. alaschanicus. There were 6 species (subspecies) of fleas that were widely distributed in the foci of all the administrative divisions (countries) of the region; There were some specific flea species in some each administrative divisions, there being 4 species specific to Haiyuan county, 1 species to Xiji, 15 to Huining county and 3 to Pingchuan district. Conclusion Citellophilus tesquorum mongolicus was the most common and stable species with a high detection rate, being dorminant in the bodies of mice, burrows and nests. So it is the major vector of the host S. alaschanicus in the foci with other rodents and birds also serving as its hosts. In particular, the exchange of fleas parasitic on birds is of great importance in the transmission of plague, which is worth exploring in terms of the epidemiology of animal plague.