In order to reveal the relationship between root nutrient content, stoichiometric characteristics and soil factors, Caragana tangutica, Berberis diaphana, Potentilla fruticose, Caragana jubata and Salix gilashanica which lived in dayekou basint of Qilian Mountain were selected as object, the stoichiometric characteristics of coarse and fine roots and their relationship with soil physical and chemical factors were studied. The results showed that the average contents of C, N and P in coarse roots and fine roots were 569.55, 7.86, 1.02 g/kg and 541.38, 8.61, 1.10 g/kg, respectively. C/N, C/P and N/P of coarse roots and fine roots were 86.63, 729.78, 9.77 and 71.34, 527.61, 8.11, respectively. The contents of C and P were higher than the average levels of Chinese plant roots, while the N content of coarse roots was higher than the average level of Chinese plant coarse roots, but the N content of fine roots was lower than the average level of Chinese plant fine roots. Soil available phosphorus content and soil mass water content were the main soil factors affecting the stoichiometric characteristics of coarse roots, while soil available phosphorus content and soil pH value were the main soil factors affecting the ecostoichiometric characteristics of fine roots.