In order to explore the factors which influence the pollutants (total suspended particulates and inhalable particulate matter) mass concentration in railway station square, with Zhuzhou railway station square as a case, makes experimental research on the relations between the total suspended particulates, the inhalable particulate matter mass concentration, people flow density and vehicle flow. The result shows that the total suspended particle mass concentration are positively correlated with people flow density and vehicle flow, whose main factor is vehicle flow, and the inhalable particulate matter mass concentration are positively correlated with people flow density, vehicle flow is not significantly correlated, whose main factor is people flow density. Bacteria and viruses with respirable particulate matter as carriers are inhaled by human body and make people sick, therefore people should try to avoid squares with high people flow density when doing activities.