Abstract: Nano-scale polycaprolactam fibers were electro-spun.The effect of voltage,distance from spinneret to collecting screen(C-SD) and concentration of polycaprolactam-formic acid solution on the configuration of the fiber was analyzed,and the relationship between the above electro-spinning parameters and the diameter distribution of the spun fiber was investigated.The results indicated that the diameter of electro-spun nylon fiber increases with the increase of the solution concentration,and the best spinning result is achieved when the concentration is 12%.When the voltage exceeds 15 kV,the fiber diameter becomes finer with the rising of the voltage,and the diameter distribution of the fiber tends to consistency.The change of C-SD makes the size of electro-spun nylon 6 fiber undulated.