Exchange between the Institute and Thailand has begun at least in 1970s at the personal level. The Japan Center for International Cooperation in Conservation has been conducting the joint research with the Fine Arts Department, Ministry of Culture (Ministry of Education at that time), Thailand, since 1992 regarding the deterioration and conservation of cultural property. Now the main study fields are Ayutthaya and Sukhothai historical parks which are inscribed in the World Cultural Heritage List.

In Sukhothai we have been conducing a research on the conservation of Great Buddha Image (Phra Ajana) at Wat Sri Chum. The core of the image is brick and the surface was finished with stucco. Formerly the surface of the Buddha image was covered by dense layer of algae and moss, and the microorganisms revived very soon if removed. In these circumstances the surface was cleaned and treated by waterphobic resin in 1998 through the on-site experiment about the effectiveness of the treatement. The image had kept good condition for several years, but the surface has gradually and partially blackened because of accumulation of dust and growth of algae.

Thus we are doing the environmental measurement and monitoring, detailed observation of the surface of the Buddha image and on-site experiments by using models in cooperation with the Laboratory of Dr. Hokoi, Kyoto University. Our study is to reveal the factors which causes such deterioration for proposing more effective way of conservation.

In Ayutthaya we studied about the deterioration of the surface of a brick wall at Wat Mahathat. Based on the result of our research, waterphobic resin was applied not at the deteriorated part but at the top of the wall to reduce the absorbencies of rain water. Now we monitor the effectiveness of the treatment, and we found the resin still keeps the effectiveness.