Wenchuan earthquake of May 12 struck China with amazement in 2008, which inflicted the devastating destruction to the public transport infrastructures in Sichuan province. Generally speaking, underground structures have the stronger seismic resistance performance compared to ground-level structures. However, seismic disasters of mountain tunnels were fairly conspicuous after the earthquake. Based on the references about tunnel earthquake damages at home and abroad (Dowding and Rozen, 1978; Huo, 2005; Rozen, 1976; Youssef, 2001; wang, 2001), more attentions should be paid to the prevention and mitigation of tunnel seismic hazards under severe intensity earthquakes. This paper describes some typical earthquake damages to mountain tunnels during Wenchuan earthquake and presents the basic characteristics of the tunnel seismic damage as well. Meanwhile, the possible reasons for the seismic damage and the corresponding measures for relieving or resisting the damage are also given.