In this study the sag-effect and the flexural rigidity of the cable are both taken into accounts simultaneously and furthermore, with the adoption and revision of the equation of motion, the time domain responses of the cable were presented and studied. In order to further examine the dynamic behavior of cable accounting for the flexural rigidity, the uniform harmonic loading was applied to the cable. Firstly, the cable is suspended on hinges horizontally and loading exerts vertically on the middle node of each curved element and then, the displacements in axial motion and in-plane vibration are calculated for the cable with solely sag-effect and with both sag-effect and flexural rigidity. It is found from the comparison of the cable responses that the ignorance of the flexural rigidity for the cable may overestimate the dynamic responses of the cable and underestimate the vibration frequency of the system, which could be dangerous for a cable-strayed structural system without accurate estimation of dynamic parameters..
