Abstract: A Nafion/pillar ［5］ composite membrane was prepared and was characterized by Fourier transform infrared analyzer, nuclear magnetic resonance spectrometer, scanning electron microscopy, thermo gravimetric analyzer.It showed that the Nafion/pillar ［5］ composite membrane had a good thermal stability, high water absorption, and low swelling ratio, and the pillar ［5］ could effectively hinder the penetration of methanol，the methanol permeability at room temperature was as low as 2.1×10-7 cm2/s. The power of direct methanol fuel cell (DMFC) with Nafion/pillar ［5］ membrane was 15.6 mW/cm2 at a current density of 65 mA/cm2.

Key words: Nafion, pillar［5］ arene, composite membrane, direct methanol fuel cell, permeability