Abstract: ［Objective］ Operating subsidies are a crucial guarantee for the healthy development of CSR (city (suburban) railways), reflecting their public service nature. The involvement of national railways in the construction and operation of CSR can optimize existing assets and leverage transportation advantages. The cooperative development model between national railways and local governments is a distinctive feature of CSR in China. To ensure the sustainable development of CSR, it is necessary to analyze the issue of operating subsidies in the context of this cooperation. ［Method］ The renovated Shanghai Jinshan Railway, and the newly-built Chengdu-Dujiangyan Railway are taken as examples to introduce their cooperation mechanisms, identifying the functional roles and responsibilities of stakeholders including local governments, CSR companies, and the national railway group. The operating subsidy models and current situations are reviewed, and key issues and primary causes encountered in the subsidy processes for the two lines are summarized. ［Result & Conclusion］ The Jinshan Railway and Chengdu-Dujiangyan Railway adopt different subsidy models—government service purchasing and deficit-oriented subsidies, respectively, resulting in differences in subsidy mechanisms and effects. Current challenges in CSR subsidies include revenue and expenditure imbalances under low fare models, inadequacies in dedicated systems and standards for CSR, and unclear asset boundaries in upgraded existing lines. Based on these issues, recommendations are proposed such as enforcing local government payment responsibilities, developing cost accounting standards for CSR, quantifying the positive externalities and overall performance of CSR, and fostering TOD (transit-oriented development) industrial chains of CSR through station-city integration.