In order to grasp performances of steel structures under marine environments, to which cathodic protection by galvanic anodes have been applied for long peirod, some cathodic protection surveys of six structures were made. The following resutls were obtained:
(1) Protection current densities calculated from anode weiht losses were 30～40% of the initial values in four structures and 40～50% in two structures.
(2) The estimated lives of the anodes were longer than the design lives in all structures.
(3) In one structure, the potentials in a part of steel members were more positive than the protective potential and it was supposed that-this was due to falling off of the anodes from the steel members near the part. In another structure, the potentials were more positive in a part, relative to those in the remaining part. That part was connected to the additional sheetpiles which has not been considered in design of the cathodic protection. The consumption of the anodes in the part of higher potential was larger than that in the remaining part.