Gel polymer electrolyte (GPE) was prepared with the porous polymer-coated separator by soaking in an electrolyte solution. The porous polymer coated on both sides of polyethylene separator was gelled in contact with the electrolyte solution and encapsulated a larger amount of electrolyte solution. The gel polymer electrolyte exhibited high ionic conductivity in order of 10−3 S/cm and was electrochemically stable up to 4.9 versus Li. With the gel polymer electrolyte, lithium metal polymer cell composed of a lithium anode and LiCoO2 cathode was assembled and its cycling performances were evaluated.