The objective of this study is to reduce the vibration oscillations on a naval vessel propulsion system driven by CODAG. Within vibration analysis of the system firstly; physical model of the naval ship's propulsion system consist of mass, spring and damping elements developed properly and the effects of dynamic forces, which are consisted of main engine stresses, and the hydrodynamic forces that come from water effect are also taken into consideration. Afterwards, equation of motions derived for each mass and consequently by solving these equations, employing matrix approach, natural frequencies and modes of the axial vibration obtained. Finally, a model for propulsion system formed in Matlab/Simulink program. The axial vibrations caused by internal and external forces that excite the system examined and illustrated with graphs how the model respond in the face of undamped and under different axial damping ratios. Then which is also our goal; axial damping ratios that can absorb vibrational motions of the system successfully determined.