The composite separator of melamine formaldehyde resin coated glass microfiber membrane was prepared for high performance lithium ion battery. It was demonstrated that this composite membranes possessed a significantly enhanced tensile strength and a modified porous structure, compared with that of pristine glass microfiber membrane. Impressive improvements in thermo-stability, with no shrinkage at an elevated temperature of 150°C. Meanwhile, such composite membrane presented a favorable wettability and remarkable electrochemical stability in commercial liquid electrolyte. In addition, the battery test results of LiCoO2/graphite cells proved the composite membrane was a promising separator with an improved cycling performance and rate capability. The cycle performance of LiFePO4/Li cells at the elevated temperature of 120°C demonstrated their excellent safety characteristic as separator in LIB, indicating the composite membrane was a potential separator candidate for high power battery.