Linear relationships between free chloride and total chloride contents in concrete are proposed based on the results of several long-term exposure tests under marine environment for various cements, such as ordinary portland cement ( OPC ), high early strength portland cement ( HES ), moderate heat portland cement ( MH ), calcium aluminate cement ( AL ), slag cements of Types A ( SCA ) and B ( SCB ), and fly ash cement of Type B ( FACB ). A high chloride-binding ability is found for AL compared to the other cements. Replacing the OPC with slag reduces the chloride-binding ability. The proposed linear relationships show reasonably good agreement with field data obtained from the wharf structures. 6 refs.