The preparation technology, basic mechanical behavior, chloride ion diffusion, steel corrosion behavior and reinforced beam column mechanical behavior of coral aggregate seawater concrete(CASC) were studied. The service life of CASC structure was analysed. The results show that cubic compressive strength of CASC can reach C80. The constitutive equations describing the whole stress strain curve of CASC under uniaxial compression was proposed. The chloride ion diffusion in CASC is characterized by high initial chloride content, high surface free chloride content and high apparent chloride diffusion coefficient.In order to reduce the risk of steel corrosion, it is recommended to choose organic new coating steel with thickness of concrete cover at least 55cm, in which concrete strength should reach C50. Comprehensively consider the influence of steel corrosion and coated steel slip, the calculation model for the bearing capacity of reinforced CASC beam column is proposed. The durability design parameters of CASC structures that meet the service life requirements of 50100 a are determined.