Calcium stannate (CaSnO3) nanofibers were synthesized by electrospinning technique combined with a sol-gel process. The structure and morphology of the as-prepared CaSnO3 nanofibers were characterized by X-ray diffraction and scanning electron microscopy, respectively. The samples had a band gap of about 3.87 eV, which was estimated by UV-Vis diffuse reflectance spectroscopy. On the basis of the experiment results, the composite fibers containing polymer and inorganic salt can be changed to pure CaSnO3 nanofibers only when they were sintered at an appropriate temperature. At the same time, a possible mechanism of the nanofibers forming process was also proposed.