Gate system is very important category in coastal irrigation structure manufactured from many different types of steel structures. The nature of the gate corrosion process is electrochemical corrosion due to the heterogeneity of materials in aggressive environments. In addition, the gate is directly influenced by microbial corrosion process. This study is mainly focused on determination the effect of the structural ratios on galvanic corrosion durability of materials for manufacturing gate, in addition, enfironmental and tide factors are also considered. The main trust of this study is to search for the appropr(ate structure ratio to minimize corrosion for work. In the experiments, samples made from two CCT 38 and SUS 304 materials with different structural ratios have been tested. The methods of qualitative and quantitative analyses have been applied to evaluate the galvanic corrosion stability of structural steels for manufacturing the gate.