Abstract The object of this study is to investigate the flow induced vibration of cable structures. Two various methods, Eigenvalue method and Cable dynamics method, are used to evaluate, the natural frequencies of structures. Vortex shedding frequencies are introduced in order to compare with the natural frequencies mentioned above. The results determine whether the phenomenon of resonance or Lock-in occur. This study has four parts. The first part is the dynamic analysis of an underwater cable Depending on the various boundary conditions, the study discusses, the system of towing cable and mooring cable in which the maximum horizontal displacement and the maximum dynamic response amplitude are found in different ocean environment. The second part is a linear Eigenvalue analysis for natural frequencies of cable structures. The third part compare the results based on the two methods , Cable dynamics and Eigenvalue method. The former obtain tension results that are important to determine the natural frequencies of structures by theoretical formula. The results of natural frequencies from the letter are compared to those in the former. The fourth part is mainly to calculate vortex shedding frequencies resulting in the relative motion between structures and fluid. The final results found in the fourth part are necessary to compare with part three, so as to determine whether the resonance or Lock-in occur.