The life of concrete structure located in complex environment depends largely on the durability of concrete. The various environmental corrosive effects are the key factor to reduce the durability of concrete structures. The studies on corrosion mechanism and detecting/monitoring technology are carried out in the world, and achieved important results. Since the 90's of last century, corrosion monitoring system for concrete structure has been put into engineering practice in the world, and the technology has been being mature. Qingdao Bay Bridge is located in the special marine environment, so corrosion is the main factor affecting the durability of the bridge. Durability monitoring is one of important aspects of the structure health monitoring and maintenance management system of the Bay Bridge. By corrosion monitoring, the critical data of concrete durability and strength degradation of the structure can be obtained. It is very significant for understanding the evolvement law of the durability, developing anti-corrosion measures, and extending the life of the bridge.