Abstract: This paper uses sulfur dioxide (SO2) as a representative pollutant to examine the impact of the high-speed rail opening on pollutant emissions of firms located around the conventional rail stations through DID method. The study finds that the opening of high-speed rail encourages firms around the conventional rail stations to reduce pollutant emissions. This conclusion remains significant after a series of robustness checks. Specifically, the passenger-cargo separation effect induced by high-speed rail opening has altered the production process of firms near the conventional rail stations. These firms gradually reduce pollutant emissions by decreasing the number of industrial boilers used，reducing the fuel consumption, improving pollution treatment efficiency, and enhancing the technological capabilities.
