Magnetic nanofibers are potentially useful for composite reinforcement, biomechanic and protective shield industries. Nanofibers with the thinner diameter have to result in higher tensile strength due to better alignments of lamellae along the fiber axis. In this book, the performance of electrospinning process was explained using response surface methodology (RSM) during fabrication of magnetic nanofibers using polyvinyl alcohol (PVA) as a shelter for maghemite where the parameters investigated were flow rate, applied voltage, gap between needle and collector and drum collector rotating speed. The response variable was diameter distribution. Central composite design was applied to optimize the variable of diameter distribution.