Abstract: In this paper, the nonlinear, nonplanar, complicated dynamics of the smallsag, iced cable subjected to side wind and movement of one support isinvestigated. Based on theories of analytical mechanics, elastic mechanicsand aerodynamics, the nonlinear partial differential equations withthree-degree-of-freedom are established. Then, the dimensionless method andthe Galerkin's method are applied to discretize the governing partialequations of a three-degree-of-freedom nonlinear system. And then, themethod of multiple scales is used to obtain the averaged equations of theiced cable system in the case of primary resonance and 2:1 internalresonances. Finally, numerical simulation is employed to find the nonlineardynamic responses of the iced cable system. It is found there exist theperiodic motion, multi-period motion, quasi-periodic and chaotic motions forthe iced cable under certain conditions.