An electrospinning method was used to fabricate poly(L-lactide-co-D,L-lactide) (PLLA) nanofiber non-woven membranes. The structure and morphology of electrospun membranes were investigated by a JEOL scanning electron microscope after gold coating. The diameter of the electrospun fiber was measured by Adobe Photoshop 5.0 software from the SEM pictures. SEM images showed that the fiber diameter and the nano-structured morphology depended on processing parameters such as solution concentration, applied electric field strength, and humidity.