We designed a feasible one-step process to synthesize heterostructures with inorganic functional materials coating on carbon submicrotubes under a mild condition. The heterostructures of carbon submicrotubes with ZnSe sheaths were successfully synthesized through the polymerization-carbonization-coating process with glucose as both the carbon source and the reductive reagent and ammonia providing an alkaline environment and acting as a soft template. The compositions of the as-obtained product were confirmed by Raman spectroscopy and XRD measurement; the morphology and microstructure were studied by SEM, TEM, and HRTEM. Room-temperature photoluminescence (PL) measurement indicates the as-prepared tubular heterostructures have a sharp and well-resolved NBE emission centered at 436 nm besides the DL emission at 589 nm, which is possibly caused by the interface associated with the combination of carbon submicrotube and ZnSe nanocrystal. One of the advantages in this process is that glucose and ammonia play manifold roles in the formation of the submicroscaled tubular heterostructures. This suggests a new path for convenient synthesis of novel tubular heterostructures with inorganic functional materials attached on carbon tubes. Furthermore, this kind of tubular heterostructure may be an ideal system applied in the fabrication of submicroscaled optoelectronics devices, and investigations on its physical properties could extend the understanding of the structure-property relationships in solids, which are in progress.