Abstract: There is increasing evidence showing that the nutrient limitation status of plant growth would shift from nitrogen (N) limitation to phosphorus (P) limitation or to N and P colimitation following longterm N deposition. Yet we know little about the ecological consequences of such changes in the relative availability of N and P. In the present study, we examined the chemistry and stoichiometry of C, N, and P in both leaves and roots of four dominant plant species in a meadow steppe of Hulunbuir, including Leymus chinensis, Stipa baicalensis, Bupleurum scorzonerifolium and Thermopsis lanceolata. Our results showed that both N and P addition had no significant impacts on C concentration in roots and leaves of all the species. Phosphorus addition showed no significant impacts on N concentration and C∶N ratios in root and leaves of L. chinensis, S. baicalensis and B. scorzonerifolium. In contrast, P addition significantly increased P concentration in leaves of L. chinensis and S. baicalensis and that in roots of B. scorzonerifolium and S. baicalensis. Nitrogen addition significantly enhanced N concentrations and decreased C∶N ratio in roots and leaves of L. chinensis, S. baicalensis, and B. scorzonerifolium, but had no significant effects on P concentration and C∶P ratio in roots and leaves of L. chinensis and B. scorzonerifolium. Moreover, N addition significantly increased the P concentration and decreased the C∶P ratio in roots and leaves of S. baicalensis. We found positive effects of N addition on  N∶P ratio of plant tissue in three out of the four species. All the examined nutrient characters in T. lanceolata showed no significant responses to both N and P addition. We found no significant interactive effects of N and P additions on the chemistry and stoichiometry of plant tissue. Results from this study highlight the role of species identity in driving the responses of plant stoichiometry to the alteration of nutrient availability, which would help predict the changes of plant community composition in the scenarios of nutrient enrichment.