Abstract: The historic response analyses of windage yaw of typical transmission line sections are carried out by means of ABAQUS software. These transmission line sections have different spans and different heights over the ground. The statistic values of windage way angle of the suspension insulator string are obtained. It is suggested that the formulation for determining the windage yaw angle of the suspension insulator string in current design code be modified by introducing a dynamic wind load factor. The factor corresponding to different cases are provided based on the results of numerical analyses.