Since 1978, the Kyoto Costume Institute (KCI) has systematically collected, preserved, researched and displayed Western European clothing. Its clothing exhibits, which have been held in many countries, are highly regarded. Various conservation/restoration techniques are used to slow the deterioration of the fabrics. In order to obtain basic information on the conservation/restoration techniques that will be used in the future, this study uses records maintained by KCI to examine the conservation/restoration of dresses from the 18th century to the 1950s and to formulate guidelines regarding costume conservation and restoration in the future. Based on records of dress conservation/restoration processes, we classified fabric conservation into four categories : (1) rear-lining or front-lining (applying a conservation cloth to one side of the item), covering, and sandwiching (placing the dress between two layers of cloth); (2) decoration conservation/restoration technique; (3) damage manufacturing/replenishing technique, and; (4) others. The results of this conservation/restoration technique analysis enabled researchers to ascertain the extent of wear of the fabric.