Soil gravel content strongly affects ecological restoration; however, the response and mechanism of plant traits to soil gravel content under the sensitive and fragile natural environment of Qinghai-Tibet Plateau remains unclear. Herein, soils with three gravel content (10%, 30%, 50%) in the southeastern Tibetan Plateau were selected, and three plant species ( one indigenous specie of Elymus dahuricus (Ed), and two introduced ones of Festuca elata ( Fe) and Medicago sativa ( Ms)) were used in seven planting patterns with different proportions ( Fe, Ed, Ms, Fe + Ed (1:1), Fe+ Ms (2:1), Ed + Ms (2:1), Fe+ Ed+ Ms (2:2:1)). Plant traits, phytochemical properties and soil stoichiometric characteristics were measured to explore the interactive effects of soil gravels and plant species on vegetation restoration. Average plant height, coverage, shoot biomass and total biomass were most affected by plant species (F=277~611, p<0.01), followed by gravel content (F=90~195, p<0.01) and their interaction (F=5~51, p<0.05); root biomass was most affected by gravel content (F=130, p<0.01). Among plant species, shoot and root biomass, total biomass overall decreased in the order of Fe+Ed+Ms˃Fe˃Fe+Ms˃Fe+Ed˃Ms˃Ms+Ed˃Ed. Plant total biomass, shoot biomass, root biomass and shoot/root ratio among different soils overall decreased in the order of low˃ high˃ medium gravel contents. All plant species were restricted by soil nitrogen except for Ed and Ed+ Ms (N:P>14). In addition, average plant height, coverage, shoot biomass and total biomass were separately negatively and positively correlated with bulk density and total porosity (r=-0.88~-0.96 and 0.78~0.91, p<0.05), so did for total nitrogen, total phosphorus, organic carbon, C:N and N:P of shoot fraction and rhizosphere soils (|r|=0.69~0.97, p<0.05), indicating that gravel content affects plant growth through bulk density and nutrients. Therefore, optimizing the configuration of soil properties (mainly nitrogen and compactness) and plant species (isecologic niche plants) is an effective strategy for ecological restoration in the Qinghai-Tibet Plateau.