Traditional festivals in Southeast Asian countries already constitute a research theme attracting the attention of scientist and cultural researchers in the region and in other countries. Many research works have been undertaken, but these are only sporadic publications in various countries. No book has yet collected together all research works done in Southeast Asian countries on traditional festivals. For that reason, this project wants to contribute to the collection and diffusion of research works done in ten ASEAN countries on traditional festivals. From the papers in the project, some preliminary comments may be made on these festivals.