In order to improve the property of sulfonated poly（pathalazinone ether ketone）(SPPEK)membrane of high sulfonation degree，proton conductor zirconium tricarboxybutylphosphonate［Zr（PBTC）］was used and incorporated into SPPEK to prepare Zr（PBTC）/SPPEK composite membranes for direct methanol fuel cell(DMFC).The results showed that the additive could reduce the water swelling and methanol permeability of membranes efficiently without sacrificing its conductivity.DMFC single cell performance demonstrated that the 30%(mass)Zr（PBTC/SPPEK composite membrane was better than the pristine SPPEK membrane for its reduced swelling and consequently improved dimensional stability.