A series of sulfonated poly(ether ether ketone)-poly(ethylene glycol) cross-linked interpenetrating polymer network/SiO2 nanocomposite membranes are developed for fuel cell application. Poly(ethylene glycol) is used as cross-linker to induce interpenetrating polymer network structure, and simultaneously, acting as a dispersant to homogeneously distribute SiO2 nanoparticles. The synergistic effect of cross-linking and inorganic additive on the membrane properties and on its performance in the fuel cell are investigated. Experimental results reveal that nanocomposite membrane have better properties than pristine sulfonated poly(ether ether ketone)-poly (ethylene glycol) membrane. Composite membrane with 10 wt% SiO2 has the best membrane properties e.g. highest conductivity of 0.185 S cm(-1) at 80 degrees C and 100% relative humidity. The instrumental characterization shows that the SiO2 nanoparticles are distributed homogeneously, and the average particle size is less than 70 nm. The membranes performance in fuel cell is increased more than twofold i.e. maximum power density of 170 mW cm(-2) at 460 mA cm(-2) and at 0.4 V for pristine membrane without SiO2 which is enhanced to 379 mW cm(-2) at 800 mA cm(-2) and at 0.47 V for membrane with 10 wt% SiO2. These results indicate that, this membrane has potential in fuel cell application.