"Restoring as the old" is one of the restoration principles for Chinese ancient books. It originates from the concept of restoring ancient books as old as they are and the principle of antiquity reparation,with the aim of maintaining the physical meaning of ancient books and demonstrating the ancient books preservation principle of intervening as little as possible. According to the principle, the original ancient books should be remained as unchanged as possible;materials and processes of restoration employed properly;and the fix results almost the same or as close as possible to the original ones. To achieve this,appropriate materials and methods are in demand.