Along with the steady increase of highway tunnels in China, the safe operation of the tunnels becomes more and more important. Besides the quality of the civil works of the tunnels, the monitoring, control and management of the tunnels play an important role in the safe operation of the highway tunnels. Taking LuntouShengwudaoUniversity Town immersed tunnel in Guangzhou as example, the author presents the components, functions, subsystem working principles and major devices and equipment of the monitoring system of immersed tunnels and expounds the importance of the monitoring system in the safe operation of the tunnels.