Abstract Rhizosphere microbes play important roles in plant performance and ecosystem functioning. It is becoming increasingly clear that rhizosphere communities vary with soil properties and variation in root traits among plant species. However, less is known about whether and how variation in root traits within plant species influences the rhizosphere microbial communities. We evaluated the intraspecific root traits variation and explored their associations with bacterial and fungal communities in rhizosphere by focusing on an ectomycorrhizal tree species, that is Pinus massoniana, in 22 sites in subtropical China. The first dimension of the principal component analysis on root traits revealed evidence for the ‘conservation’ gradient of the root economics space. Overall, root traits explained more variation in fungal communities than in bacterial communities in the rhizosphere. Functional composition of rhizosphere microbial communities changed significantly along the ‘conservation’ gradient, with fast‐growing copiotrophic bacteria and symbiotic ectomycorrhizal fungi were significantly enriched on the ‘acquisition’ side, while slow‐growing oligotrophic bacteria were significantly enriched on the ‘conservation’ side of the gradient. Synthesis: Our study demonstrates that intraspecific variation in plant roots significantly influence rhizosphere microbial communities, which in turn can influence plant nutrition and therefore plant performance within the community.