A series of polyurethane prepolymers terminated with hindered phenol AO-80 and AO-2246 were designed and synthesized, and polyurethane damping materials were prepared by curing reaction. The structures of damping materials were characterized by FT-IR, DSC, SEM. The influences of amounts and types of hindered phenol, and molecular weight of polypropylene oxide were investigated on dynamic mechanical properties of the polyurethane damping materials. The results of dynamic mechanical analyses show that the compatibility between hindered phenol and polyurethane is good. As the amounts of hindered phenols increase, the glass transition temperature of the polyurethanes rises, the maximum damping factor increases and the damping temperature range broadens. The maximum damping factor and loss peak area of polyurethane damping material terminated with hindered phenol AO-2246 are larger than those of polyurethane damping material terminated with hindered phenol AO-80. the maximum damping factor of the polyurethanes increases and glass transition temperature decreases with the molecular weight of polypropylene oxide increasing.