This report presents a summary of the methods and techniques used in the survey and describes (1) the physiographic regions of Thailand and their occurrence within the study areas, (2) the great soil groups identified in this survey, (3) the map units and the occurrence of these map units in the physiographic regions of Thailand, and (4) the general soil conditions of Southeast Asia. Interim reports for each of the seven study areas were prepared and are included as Appendices A through G in volume 2 (AD-488 315). Each report includes a general description of the environmental conditions of the study area as related to the individual soils mapped. The maps presented in the appendices are to be considered as reconnaissance soil maps because of the small map scale used and the minimum amount of work performed in the field, particularly in areas without reasonable access routes.