The delpletion of fossil fuel and enviromental pollution have led to an urgent demand for alternative energy sources and more efficient energy conversion methods. Fuel cells are a kind of electrocemical devices that can convert the chemical energy of fuels to electrica energy directly. The advantages of the fuel cell technologies are their high energy utilization efficiency and very low pollutant emissions. Proton exchange membrane fuel cell (PEMFC) is one of the most promising clean energy technologies under development in fuel cell families. The conventional PEMFCs are normally operated at low temperatures (~80 C). Currently, a veryhot research topic is to increase the working temperature of PEMFCs to above 100 C, because the high temperature operations can provide many advatages such as improved electrode reaction kinetics, enhanced tolerance of catalysts to CO poisoning and simplified water management, etc. However, the biggest challenge for high temperature PEMFCs is to develop an excellent high temperature proton excange membrane (HT-PEM). In my group, mesoporous PEMs were developed and applied for application in PEMFCs, especially in high temperature PEMFCs. The many good results and achievements obtained indicate that the mesoporous PEMs are promising for application in high temperature PEMFCs.