Abstract: Provided are a hydroxyl group-containing sulfonated polyethersulfone copolymer, a method for preparing the same, a polymer electrolyte membrane for fuel cell, and a membrane electrode assembly including the same. More particularly, provided are a hydroxyl group-containing sulfonated polyethersulfone electrolyte membrane and a membrane electrode assembly including the same, which are applied to a fuel cell to provide significantly higher ion conductivity as compared to the sulfonated polymer electrolyte membranes according to the related art. The hydroxyl group-containing sulfonated polyethersulfone copolymer electrolyte membrane shows significantly higher ion conductivity under various temperature and humidity conditions as compared to the sulfonated polymer electrolyte membranes according to the related art. Therefore, it is expected that the hydroxyl group-containing sulfonated polyethersulfone copolymer substitutes for expensive fluoropolymer electrolyte membranes such as Nafion.