The pressurized smoke control system is important for fire safety in building because it is directly concerned with egress time of people. Even though the damper plays an essential role in the pressurized smoke control system, the research for a position of damper effects on distribution of air flow at the compartment door is not performed. In this study, numerical simulation using FDS 5.0 was carried out to analyze the effect of the position of damper on flow distribution at the compartment door. To simulate real situation, effects of opening and closing of compartment door was considered. When the damper is on the opposite wall of the compartment door, the back flow to the lobby is large compared to the two other cases of damper position.