In the current research project, we have synthesized a novel Sb/Carbon nanocomposite with 3D porous structure which is successfully applied to the Li/K-ion batteries as anode materials. The unique structure shows the homogeneous Sb nanoparticles embedded into a 3D porous carbon (Sb@PC), relieving the intense volume expansion of inner Sb alloying and contributing to the integrity of the structure. As anode materials of Li-ion and K-ion batteries, they both showed an excellent electrochemical performance.