The gap between demand and supply of water and the risk of environment pollution associated with inadequate decentralized treatment and disposal of sewage have stimulated attempts to develop in-situ sewage treatment systems, highly efficient in performance with respect to not only SS, organics and bacteria, but also nutrients, low in energy consumption, and easy in operation and maintenance. The subsurface soil infiltration system introduced in this paper may offer a solution to the problem. This paper described the process of the subsurface soil infiltration system, analyzed the mechanisms for sewage purification and the effects of various factors on treatment, discussed a number of problems related to soil clogging and pathogenic and Nitrate-N contamination of the groundwater. The prospect of the technology was expected as a conclusion.