In order to explore the response of dominant species and rhizosphere soil stoichiometric of typical grassland in the Loess Plateau to different precipitation treatments, the typical grassland fenced for 20 years in Yunwu Mountain, Guyuan, Ningxia was selected as the research object, using shelter technology to simulate three different precipitation gradients (50%, 100% and 150% of natural rainfall). The content of total carbon (TC), total nitrogen (TN), total phosphorus (TP), rhizosphere soil organic carbon (RSOC), total nitrogen, and total phosphorus in the aboveground and underground of the dominant species Stipa bungeana, Potentilla acaulis and Artemisia sacrorum were analyzed, The correlations between the stoichiometry of each dominant species and rhizosphere soil stoichiometry were analyzed. The results showed that (1) the above and below ground total C content and above ground N content of the three dominant species were all higher under 50% precipitation, while the above and below ground P content and total P content in Potentilla acaulis were the highest under 100% precipitation. (2) Compared with the treatment of 50% and 150% precipitation, the aboveground C/N, C/P of Stipa bungeana and the underground C/P of Potentilla acaulis and Artemisia sacrorum were significantly different (P<0.05); the N/P of dominant species under 150% precipitation treatment was significantly higher than that under 50% precipitation (P<0.05). (3) The contents of C and N in the rhizosphere soil of the three dominant species were higher than those in the Loess Plateau soil, and the content of C in the rhizosphere soil under 150% precipitation was significantly higher than that under 50% precipitation (P<0.05). Increasing precipitation treatment indicated higher C/N and C/P of the rhizosphere soil of the dominant species than decreasing precipitation treatment, but with smaller changes in N/P. (4) Under 50% precipitation treatment, there was a negative correlation between the N content and the C content in the rhizosphere soil of Artemisia sacrorum and Potentilla acaulis, both above and below ground (P<0.05). Under 100% precipitation treatment, the total C, N, P contents of the dominant species were strongly correlated with the C, N, and P contents of the rhizosphere soil (P<0.05). Under 150% precipitation, the underground C content of dominant species was negatively correlated with its N content in rhizosphere soil. (5) The absolute value of negative correlation coefficient between N content in rhizosphere soil and underground N content of the three dominant species was greater than that between P content in rhizosphere soil and underground P content. The research results will provide a scientific reference for understanding of the material cycle of typical grassland ecosystems in the Loess Plateau and judgment of vegetation nutrient limitations.