In this study, hydro-structural behavior of three types of marine circular cofferdam system of single steel-plate, corrugated steel-plate, and double steel-plate was investigated analytically. As a result of the study, it was found that the single steel-plate type was vulnerable to the cross-section deformation, the corrugated steel-plate type was deformed in the axial direction, and the double steel-plate type was vulnerable to the local deformation, respectively. Also, the corrugated steel-plate type indicated lower total shear force than plane steel-plate type since the waveform of the corrugated steel-plate caused the diffraction effect on the wave action. Based on the hydro-structural behaviors, advanced cross-section of large circular cofferdam system will be proposed so as to secure structural safety under marine condition.