Abstract: Aiming at the characteristics of poor economic foundation and decentralized discharge of residential sewage in wide rural areas in China, integrated wastewater treatment equipment named purification tank (Johkasou) which originated from Japan was analyzed. After decades of continuous development, purification tank technologies were getting mature in Japan. A series of reasonable laws and regulations system, technical standards system and service system in the management of the purification tanks had been formed, which had supported and regulated the technological dissemination and application of purification tanks. Purification tank has the characteristics of easily-installed and flexibly operated. These characteristics are suitable for the decentralized rural sewage treatment in China. The development, existing processes, new technologies, applications and managements of the purification tank in Japan were analyzed. Some revelations for China, especially for Liaohe Conservation Area, in applying decentralized wastewater treatment methods were pointed out.