Abstract: There were many articles which revealed the regulation of animal populations,but there was not the article that in same condition researched into effects of many factors on density of population at same time.Our work was carried out in Minqin Experimental Station of Adminstering Desert from April to mid-June in 1989.In order to study that action administered desert by human,vegetation,potential available food resources,densities of competitive species and physical and chemical characters of soil affect population density of Phrynocephalus przewalskii.The results showed that it was in significant that the action administered desert by human affects population density of Phrynocephalus przewalskii.The potential available food resources,vegetation,the moisture of soil,the densities of competitive species are determinate factors which affect population density of Phrynocephalus przewalskii.Because the changes of population density of Phrynocephalus przewalskii along with any changes of these factors,these factors all have the effects on regulating population.