The diameter of the starch fibers produced by electrospinning is a key parameter for most potential applications. In this study, a quantitative relationship between fiber diameter and certain electrospinning parameters, i.e. starch concentration, applied voltage, spinning distance and feed rate, was established by empirical modeling using a fractional factorial experimental design in a constrained region. Response surface methodology was employed to analyze the interactions of the electrospinning parameters and predict the direction to minimize and maximize the fiber diameters. (C) 2012 Elsevier Ltd. All rights reserved.