We demonstrate a one-pot hydrothermal cohydrolysis-carbonization Process Using glucose and iron nitrate as starting materials for the fabrication of carbonaceous spheres embedded with iron oxide nanoparticles. It is verified by TEM, Fe-57 Mossbauer, and Fe K-edge XAS that iron oxide nanoparticles are highly dispersed in the carbonaceous spheres, leading to a unique microstructure. A Formation mechanism is also proposed. This route is also applicable to a range of other naturally occurring saccharides and metal nitrates. A catalytic study revealed the remarkable stability and selectivity of the reduced FexOy@C spheres in the Fischer-Tropsch synthesis, which clearly exemplifies the promising application of such materials.