Ice shedding on transmission lines will result in the longitudinal unbalanced forces on the adjacent transmission towers, which significantly threatens the safety of transmission lines.The methodologies to simulate the transmission line system, ice-accretion, and ice-shedding are developed using finite element method.The finite element model of a nine-span transmission line is built and ice-shedding on transmission line with 15 mm ice thickness is simulated.Then the responses of the transmission line system due to ice-shedding from the conductor and ground wire are obtained.Results from this study show that ice-shedding causes large-amplitude jump of the transmission line and significant impact on the adjacent transmission towers.Meanwhile, the longitudinal unbalanced fo rces induced by simultaneous ice-shedding from the ground wire are greater than those from the conductor.