Global change apart from ecosystem processes also influences the community structure of key organisms, such as arbuscular mycorrhizal fungi (AMF). We conducted a 3-year experiment where we suppressed with benomyl mycorrhiza to understand how AMF alter the plant community structure under warming and nitrogen (N) addition. The elemental content and foliar tissue stoichiometry of the dominant species Leymus chinensis and the subordinate species Puccinellia tenuiflora were studied along with soil nutrient stoichiometries. Overall, N addition enhanced plant N: phosphorus (P) ratios at a greater level than experimental warming did. Under global change conditions, AMF symbionts significantly increased soil available P concentrations, promoted plant P absorption and decreased the plant N:P ratios. AMF alleviate P limitation by reducing plant N:P ratios. Our results highlight that the negative influence of global change on plant productivity might cancel each other out through the additive effects of AMF and that global change will increase the dependency of plants on their mycorrhizal symbionts. Unlabelled Image • N supply increased plant N:P ratios. • Effect of N supply on plant stoichiometry was stronger than that of warming. • AMF increased soil available P concentrations and promoted plant P absorption under global change. • AMF alleviated P limitation by reducing plant N:P ratios under global change conditions. • The negative influence of global change on plant productivity might cancel each other out through the presence of AMF. [ABSTRACT FROM AUTHOR]