Abstract: The research was carried out on the optimal sensor placement of the Guangzhou New TV Tower (GNTVT), the highest TV tower in the world. To avoid the computation of a large dense matrix in the dynamic analysis, a three dimension finite element model of the GNTVT was first simplified to equivalent series multi degree-of-freedom (DOF) system. Considering that the sensors can only be arranged in the horizontal direction of the structure, but not in the torsional direction, the new thoughts of taking the horizontal DOF as the master DOF and torsional DOF as the slave DOF, and reducing the slave DOF by a model reduction were proposed. Then, the simplified model after reduction was obtained by the comparison of the reduction results of Guyan, Kuhar, IRS and IIRS methods. Finally, the plan of the optimal sensor placement of the GNTVT was obtained after analyzing the implementation process of the dual-structure codes-based generalized genetic algorithm and performing the parameter analysis.