Abstract: The scaling of recirculated water and its corrosion to the recirculated water system have been described on the theory base. It is pointed out that the formation of scale mainly depends on the carbonic acid calcium that the recirculated water contains. The judgement of the sediment deposite of scale and the control of scale and corrosion are introduced. Some effective methods have been given, for instance, decreasing the carbonate's hardness for the scale of recirculated water, thermal deoxidization, adding inhibitor and covering the metal surface with coating materials for the corrosion control of the system. The optimal program proposed is to jointly control the corrosion of scale to protect the recirculated water system, which can enhance the quality management and elongate the service life of the recirculated water system.