A growing population and increasing urbanization over the past century have made it difficult to locate suitable ground for siting infrastructures in densely populated areas. The Deep Mixing Method (DMM) was developed and put into practice in Japan in 1975 to cope with the headaches of stability and/or excessive settlement in soft soil areas. This method involves using cement and/or lime as a soil stabilizer, added in-situ to deep soils, and has now been adopted not only in Japan but in the USA and other parts of the world as well. This book presents properties of this treated soil method, its various applications, its design and execution, and accumulated research results over the last twenty-five years.