Many existing traffic signal control systems are of a hierarchical structure employing the concept of subsystems or sub-zone signal control. Therefore, network partitioning becomes an important task of such an urban traffic signal control system. However, urban traffic signal control network partitioning is a multi-objective and multi-constraint problem, which has been shown to be a NP-hard problem. This paper presents a partitioning method using the spectral methodology according to the correlation degree of each link. Two measures are adopted in this problem: modularity and average cut weight. The developed method has been tested on two networks, including a computer-generated network and real-world road network. The results show that the spectral bisection is a reasonable network partitioning method to support urban traffic signal control.