Lanthanum cuprate nanofibers and barium titanate nanofibers were synthesized by electrospinning utilizing sol-gel precursors. The effects of electrospinning parameters (ceramic precursor concentration and electric voltage) on fiber diameter before/after calcinations were investigated in detail for lanthanum cuprate nanofibers. A series of experiments designed by response surface methodology shows as dried fiber diameter increases calcined fiber diameter increases. As voltage decreases and ceramic precursor concentration increases, dried fiber diameter increases for most combinations of voltage and precursor concentration. But there are also conditions available where the opposite is true. This chapter explains how contradicting reports on fiber diameter dependence in the literature can be unified in a larger picture. Furthermore, the microstructure evolution in the nanofiber was studied. The morphology, microstructure and crystal structure were investigated by SEM, TEM and XRD.