In this study, gelatin nanofibers that were stable against hydrolytic degradation environment were prepared via electrospinning of aqueous fish gelatin, an eco-friendly sugar crosslinking agent, and a mild heat treatment crosslinking process. Next, the formation of the Maillard reacted products according to the sugar type and the physicochemical properties and antioxidant functions of the sugar-crosslinked gelatin nanofibers were investigated. The addition of sugar to the gelatin nanofibers increased the Maillard reactivity in the order of sucrose < glucose < fructose, thereby increasing the stability of the gelatin nanofibers against hydrolytic degradation. In addition, sugar crosslinking enhanced the mechanical properties, wetting and hygroscopic properties of the gelatin nanofibers. Moreover, due to the production of Maillard reactants, the sugar-modified nanofibers exhibited an excellent antioxidant effect compared with existing gelatin nanofibers.