Abstract: The operation status and passenger flow development of Nanjing rail transit is briefly described. With the big data of rail transit, the spatialtemporal distribution characteristics of Nanjing rail transit passenger flow are analyzed, and the distribution pattern is studied. Results show that urban rail transit and suburban rail transit lines present different passenger flow characteristics. The morning peak hour coefficient of urban rail transit lines on weekdays is generally between 15% and 20%, while the morning peak hour coefficient of suburban rail transit lines is generally lower. The peak hour coefficients of both urban and suburban rail transit lines are generally not significant on weekends (not holidays). Line peak hour maximum passenger flow section is basically observed near interchange station.