Green nanofiber membranes were fabricated from blends of soy protein using electrospinning method. Soy flour was purified using a lab-scale filtration process to obtain purified soy flour (PSF) with higher protein content, which was blended with Polyvinyl alcohol (PVA) and Polyethylene oxide (PEO) to electrospin nanofibers. The composition of polymer solution was varied by varying the molecular weights of PVA and PEO and their concentrations, using various forms of soy protein (SPI, SPC and PSF) over a range of concentrations, varying the type and amounts of surfactants, and using various additives to reduce gelling in soy protein/PVA blends. The process parameters applied voltage, needle tip-collector distance and solution flow rate were also varied to determine their effect on fiber diameter and distribution. The individual and interaction effects of solution concentration, PVA molecular weight, applied voltage and needle tip-collector distance were determined using statistical analysis. Concentration, molecular weight and needle tip-collector distance were found to have a significant effect on fiber diameter, whereas effect of applied voltage was insignificant. Solution flow rate was observed to affect the size and uniformity of fibers. Beads and flat fibers were observed at low and high flow rates. The mechanical properties of electrospun membranes were measured to determine the effect of increasing soy protein content and PEO content on the strength and modulus of the membranes. The strength and modulus were found to increase with increasing membrane cohesion and protein content, while the strain at break increased with increasing PEO content. The biodegradability of electrospun membranes was studied by composting films of SPC/PVA and SPC/PEO over five weeks. It was observed that the loss in weight of the membranes was only about 3-4%, even though soy protein is known to degrade fast.