The Deep Mixing Method (DMM), a deep in-situ soil stabilization technique using cement and/or lime as a stabilizing agent, was developed in Japan and in the Nordic countries independently in 1970s. Numerous research efforts have been paid in these areas investigating properties of treated soil, behavior of DMM improved ground under static and dynamic conditions, design method, and execution techniques. Due to its wide applicability and high improvement effect, the method has gained increased popularity in many countries in Europe, Asia and in the USA. New types of technologies have been developed in the last 10 years and put into practice; e.g. high pressure injection mixing type of DM and combined type of DM with mechanical mixing and high pressure injection mixing technologies. The design procedures for the DM methods were standardized in several organizations in Japan and revised several times. Information on these rapid developments will benefit those researchers and practitioners who are involved in ground improvement throughout the world. The book presents a State of the Art on the Deep Mixing methods that covers recent technologies, research activities and know-how in machinery, design, construction technology and quality control and assurance. The Deep Mixing Method is a useful reference tool for engineers and researchers involved in DMM technology everywhere, regardless of local soil conditions and variation appliations.