Abstract: Aiming at geotechnical problems in the redevelopment of industrial contaminated sites, the research achievements from the author and his group are throughly summarized. The researches includes five aspects: (1) Changes of fundamental behaviors of contaminated soils and contaminated site classification from the perspective of engineering properties. The physical and mechanical properties of heavy metal-and organic-contaminated soils are presented. Based on the risk assessment of contaminated sites as well as methods for soil classification in the literatures, the index classification for contaminated sites is developed using the analytic hierarchy process structure. (2) Application of piezocone penetration test (CPTU) to in-situ testing in contaminated sites. The resistivity characteristics of contaminated soils, testing methods for resistivity piezocone penetration tests in contaminated sites and permeability parameter evaluation for contaminated soil layers using CPTU are stated. (3) Advanced solidification/stabilization technology. Mechanisms of solidification/stabilization of heavy metal-contaminated soils are revealed. The effects as well as limitations of cement-based solidification/stabilization are illuminated. Phosphate-based binder and alkali-activated slag for solidification/stabilization of high-level heavy metal-contaminated soils are developed. Great effort on the improvement of solidification/stabilization construction technology has been conducted to enhance the engineering properties and environmental safety. (4) Treatment of organic-contaminated sites using air sparging. The air phase motion, treatment mechanism and treatment effect are understood via 1-D and 2-D air sparging model tests, and a design method for air sparging is established based on the