Abstract: A series of poly(acrylic acid) copolyester/graphene latices were prepared by in?situ polymerization using graphene, acrylic acid (AA), methyl acrylate (MA) and ethyl acrylate (EA) as raw materials, and a composite electrode sheet was prepared by a fabric impregnation method. The effects of graphene and monomer contents on the electrical conductivity, flexibility, mechanical properties and electroencephalography (EEG) monitoring performance of the composite electrode sheet were investigated by using Ohm meter, differential scanning calorimetry, universal material testing machine and EEG tester, and its morphology was observed by scanning electron microscopy. The results indicated that the prepared composite electrode sheet exhibited good flexibility at a graphene content of 46.5 wt%, a reaction temperature of 80 °C, a reaction time of 3 h, and an AA/MA/EA volume ratio of 0.2/1/1.8. In this composite electrode sheet, and the fabric was made from the non?woven fabric impregnated by copolyester emulsion. This composite electrode sheet exhibits good electrical conductivity and mechanical strength at room temperature and is suitable for the use in EEG monitoring, and its signal intensity and stability for EEG is similar to the commercial Ag/AgCl electrode. There is no conductive paste needed for this composite electrode, so it is more convenient for use without any skin contact.