Abstract: Strong pressure fluctuations are induced when the train passes through the tunnel at high speeds, which causes aural discomfort for passengers and crews, known as the internal pressure comfort environment problem. In this study, field tests are carried out to obtain the internal and external pressure variation characteristics of the 350 km/h China Standard EMU (electric multiple unit) passing through the tunnels on a specific line. The pressure comfort environment is described using the internal maximum pressure variation within 1 s, 3 s, 10 s and 60 s, i.e. Δp/1s, Δp/3s, Δp/10s and Δp/60s , and the time history characteristics are investigated. Influence of the line slope, tunnel length, train speed and “tunnel group” on the internal pressure comfort environment are analyzed, and the relationship between the sealing efficiency of the train and the aural discomfort is discussed. The results provide a good foundation for further cognizing high-speed trains’ pressure comfort environment as well as its design and control.