Abstract: Objective With the rapid networked development of city railways, higher demands are being placed on the railway signaling systems in terms of interoperability and minimum headway. Currently, the main signaling system solutions for city railways in China are the CTCS-2（China train control system level 2） + ATO（automatic train operation） system and CBTC（communication-based train control） system. Targeting the current state of networked development in Shanghai city railway network, it is necessary to conduct a comparative analysis of these two solutions and propose suggestions on signaling system selection for Shanghai city railway network. Method The planning background and networked operational requirements of Shanghai city railway network are analyzed, and the construction experiences of city railways in major Chinese cities are summarized. The technical characteristics and applicability differences between CTCS-2 + ATO and CBTC systems are compared from multiple aspects. Through quantitative analysis of the key factors affecting system operational efficiency, simulation methods are employed to verify their actual performance. Considering interoperability needs of Shanghai city railway, the adaptability of each system in interoperability scenarios is evaluated from three perspectives: compatibility with the national railway system, city railway synergy cross provinces and network integration capability within internal lines. Result ＆ Conclusion Shanghai city railway network requires both high network efficiency and interoperability. However, with demonstrated superior operational efficiency, the CBTC system has weaker interoperability capabilities. Conversely, the CTCS-2 + ATO system exhibits better interoperability performance but has limitations in further reducing headways, which imposes pressure on meeting longterm capacity demands. It is therefore recommended that Shanghai city railway lines connecting with external networks adopt the CTCS-2 + ATO system, while internal lines with high capacity requirements use the CBTC system to meet both current efficiency and interoperability demands of the network.