Paper cultural relics have extremely high value in research and collection. However, as the time goes on and the environment changes, there will be unfavorable conditions on paper relics, like yellowing, moulding, chalking, aging and embrittlement to some extent. Nowadays, the protection and repair of paper cultural relics are the research emphasis in the field of relics protection. The modified Polyurethane (PU) is an effective material for protecting paper cultural relics and overcome the disadvantages of traditional PU material, including poor polar-solvent resistance and poor heat resistance. Therefore, in this article, the synthesis, properties, applications of modified PU material were summarized and prospects for the research development in the future were look forward
