Using ABAQUS software, three dimensional finite element model of a transmission tower-line system is created. Nonlinear seismic responses under three seismic records with and without strain rate effect are studied. The results show that the strain rate effect on the transmission tower-line system is more obvious with an increase in intensity of the earthquake. The influence of strain rate on the top displacement and base shear of tower under certain seismic records is unneglectable. Also, it is shown that the strain rate effect on the deformation of wire is prominent. The strain rate effect on the axial force of wire is neglectable. This simple study reveals the importance of considering strain rate effect in seismic analysis for transmission tower-line system.