With the development of transportation, the road and railway tunnels are more and more in the world. But great loss due to the tunnel fires happened in recent years shows that the tunnel fire safety is a problem. Realizing the characteristics of tunnel fires is very important for the tunnel fire protection. In this paper, given a tunnel, the smoke development in different situations was simulated using zone model (CFAST) with the multi-cell concept and field model (FDS). The smoke temperature distribution and smoke layer interface height were discussed. And the comparisons between these two models were made. The harm of fire and smoke to people and tunnel lining at different position was also discussed.