Four types of nanofibrous filters, EPN-1. EPNPAC-2, EPN-3, and EPNPAC-4, were investigated in this trial, respectively. The microstructures of nanofibrous filters were analyzed through a scanning electron microscope (SEM), while their elements were determined by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The Zeta potential, specific surface area, porosity and permeation flux of nanofibrous filters were measured in this study. The isoelectric point and pure water permeability coefficient were also calculated. The result shows that the nanofibers are less than 5 pm and are made up of gamma-Al2O3, silicate and polyester. The electropositive filter is that the nanofiber contains gamma-Al2O3. The nanofibers have different positive and negative charge at different pH. The specific surface areas of nanofibers are 625.58, 509.13, 850.27 and 780.23 (m(2)/g), respectively. The porosity of nanofibrous filters are less than 70%. Pure water permeability coefficients of filters are 80.84, 64.03, 119.17 and 100.26 (L.m(-2).s(-1).MPa-1), respectively. The performances of nanofibers without nano powdered activated carbon (PAC) are better than those with nano PAC. Crown Copyright (C) 2010 Published by Elsevier By. All rights reserved.