Abstract: In order to study the impact of mine fire on tunnel ventilation, the software of fire dynamics simulator（FDS) is applied to examine the mine fire's effects upon the ventilation of the level and uplink tunnels.The results show that the fire leads to the change of the air movement.According to distribution of the air velocity in tunnel, the tunnel can be divided into four regions.It can be seen through analysis that  the throttling effect exists in the level tunnel, but its buoyancy effect can be ignored; While both the throttling and buoyancy effects exist in the uplink tunnel, and the throttling effect is increased obviously with the power of heat release increasing.

Key words: Mine fire, Tunnel ventilation, Fire dynamics simulator, Buoyancy effect