The structural durability limit states which can be used in the structure design are proposed by summarizing existing definition about durability and durability limit states and considering the characteristics of harbor structures. For the ordinary RC elements and pre-stressing beams and slabs made with deformed bars, it is proposed that the threshold values of decreased bearing capacity, increased deflection and longitudinal crack width are taken as the control parameters for the structural durability limit states. For pre-stressing RC components with steel wires and pre-stressing RC piles with deformed bars, the time at depassivation of reinforcement bars is taken as the durability limit state.