Abstract: The paper deals with the relationship between the body temperatures of Phrynocephalus przewalskii (Sthauch) and Eremias multiocellata (Guenther) and the environmental temperatures,their selections of environmental temperatures and their resistance against low and high temperatures.The body temperatures of przewalskii and Multiocellata were negatively interrelated to environmental temperatures (P<0.001).Under the same temperatures.The body temperatures of przewalskii were 3 ℃ higher than that of multiocellata.The environmental temperatures selected by the former were 38-40 ℃,whereas the latter required only 35-37 ℃.The hot and dead temperatures of przewalskii were higher than those of multiocellata.The threshhold of the hot and dead temperatures in przewalskii varied from 44 ℃ to 48 ℃ and its highest dead temperature (TL50) was up to 48℃,and that in multiocellata was 42-46 ℃ and its highest hot temperature (TL50) was 46 ℃.The ability that two species can resist against low temperatures was equal.The cold and dead temperatures varied from 0 ℃ to -3 ℃.The cold and dead temperatures (TL50) of przewalskii were -2.3 ℃,but those of multiocellata were -2.5 ℃.These significant differences between the two species are concerned with the characteristics of each,habitats and sizes of the bodies.