Abstract: According to classical similarity theory, based on the time-varying denaturation of surface chloride concentration, the similarity relation in time between actual environment structure and artificial erosion acceleration simulation environment test structure was established.After taking powder in marine concrete components and specimens respectively, measured the surface concentration of chloride ion by RCT and analyzed its time-varying model.Finally the expression of time similarity coefficient is put forward and its value is calculated, it provides the basis for life prediction of service structure.

Key words: time similarity relation;surface chloride concentration;time-varying model;salt fog zone;cyclic wetting and drying zone