Abstract: This paper presents a case history of the corrosion study of the groundwater on an underground concrete structure in the coastal area of Zhanjiang. Usually, the groundwater in the coastal area is medium to strong corrosion to the concrete; however, the some chemicals in the groundwater serve retarders for the rate of the sulfate crystallization process. This retard process creates a favorable condition for the corrosion.The comprehensive analysis on the groundwater indicates that the groundwater has only weak corrosion to the concrete structures.

Key words: Retarding Effect, Comprehensive Evaluation, Corrosion, Concrete Structure