This article presents an overview of recent research about pore filling membranes applied to fuel cells. Polymer electrolyte fuel cell is a promising energy conversion devise with high efficiency although a high performance electrolyte membrane is still necessary to make this device prevailing technology. Pore filling membrane is a concept to compensate mechanical strength and to control the state of water or nanostructure of the filling material. The technology leads to develop next generation fuel cells operate at low temperature.