Sangyangmun is a written record which inform the date, time, history and reason of constructing a wooden building. We have conserved Sangyangmun which was discovered during the repairment and restoration of wooden building. From 1998 to 2002, We have completed the conservation of 27 pieces of 13 cases, for example Daeung-jeon, Bongjeonsa-Temple. First We investigated the material or damage condition of Sangyangmun, and carried out fumigation in order to prevent insects and fungi. Then Sangyangmun must be sealed hermetically using escal film in order to prevent the second damage.