In this article, the authors retrospect the definitions of Sustainable Tourism Development (STD) in different international documents, and traced the theoretical source of STD from different schools of learning in Economics, Tourism Sociology, Tourism Anthropology, Environmental and Eco Ethics. The author analyzed different value pursuits of STD, and discussed different STD based on utilitarian value, justice value and conscience value. The author also gave a brief comment to the situation of STD research and practice based on different value in China today.