The oriented polypropylene fibers in this article were fabricated via the needleless melt electrospinning technique, and the influence of arrangement for oriented fiber membranes on the filtration efficiency was studied using it, guided by an electric field simulation with the software ANSYS, then combined with an experimental study to investigate the influence of the nozzle-to-electrode distance and the electrical field strength on fiber diameter. An appropriate distance to electrospun oriented fibers in the range of 5-10 cm was determined, and it was shown that the fiber diameter significantly became thinner with the increasing cylinder speed. Characterizations revealed that the mean pore size of the electrospun oriented membranes was much smaller than the electrospun random membranes, and the mean pore size of oriented membranes and random membranes was 18.96 mu m and 27.29 mu m, respectively. Experimental results demonstrated that electrospun oriented membranes showed higher efficiency in rejecting the 0.5 mu m particles with a diameter of 2.49 +/- 0.418 mu m and still maintained nearly the same permeate flux as that of the native membrane. The interval angle of adjacent membranes was more uniform, and the water flux and rejection ratio would be greater. (C) 2014 Elsevier B.V. All rights reserved.