Abstract: Blend proton exchange membrane with polyhedral oligomeric silsesquioxane (POSS) star topological structure block copolymer graphene oxide (GO)/polyhedral oligomeric silsesquioxane-(polymethylmethacrylate-block-polystyrene)(POSS-(PMMA₂₆-b-SPS₁₅₆)₈) was prepared by the blending method. The effects of GO content on the properties of blend proton exchange membrane were investigated by testing ion exchange capacity (IEC), proton conductivity, water uptake and swelling rate. It is found that the ion exchange capacity of the blend proton exchange membrane increases with the increase of GO content, while water uptake and swelling rate reduce with adding GO. The blend proton exchange membrane shows higher dimensional stability in the determination of temperature range. The decline of the conductivity of pure polymer membranes owing to water loss in 80℃ can be improved by adding GO. The proton conductivity of proton exchange membrane can be improved, It is found that the proton conductivity of the blend proton exchange membrane with 0.3wt% content of GO is approximately 3.2 times bigger than that of the pure polymer membranes in 100% relative humidity at 80℃.