Sustainable development of geologic resources in Thailand requires multidisciplinary studies. This paper describes : (1) weaknesses of traditional system of education in Geoscience in Thailand and (2) needs of multidisciplinary studies to educate Thai geoscientists for the twenty-first century. Problems in educating Thai geoscientists include : (1) lack of multidisciplinary practice and (2) lack of communication in English. My experience at Colorado School of Mines and Texas A&M University suggests that the future education for geoscientists will be interdisciplinary. Multidisciplinary studies provide complete information for decision makers to decide how to sustain geologic resources and save the environment. These multidisciplinary studies involve : (1) basic geology, (2) environmental science and management, (3) environmental geology, and (4) mineral and environmental economics. Interdisciplinary training must be supported. Working as a team is an important key to success. Multidisciplinary studies may be the best way to sustain geologic resources of Thailand and to protect the environment in the next century.