Thai-Danish botanical research collaboration started over 100 years ago with Schmidts work on the flora of Koh Chang. In the 1950es the collaboration was fortalized with the initiation of the Flora of Thailand project. The collaboration was for many years centered in the Royal Forest Department in Bangkok and involved a large amount of collaborative fieldwork, graduate and post-graduate training, and publication. Over the years the collaboration has been extended to several other institutions and universities. Recent activities of Aarhus University have involved joint graduate training with Chiang Mai University, which is the subject of this presentation. Three graduate students have completed their doctoral training with research projects covering botany of ethnic groups in Thailand, taxonomic and ecological studies of Thai Nymphaeaceae, and ecophysiological studies of aquatic plants. Two projects involving ethnobotanical studies are still under way. The funding for these projects has come from the Royal Golden Jubilee Program, Chiang Mai University and Thai Government stipends, and from Aarhus University..