Based on the detailed disaster investigation in eastern Gansu province after Wenchuan Ms8.0 earthquake, the earthquake damage in the area is classified and researched, the seismic damage intensities and destruction features for different kinds of building and engineering structure are presented. According to the unique geological conditions, the reasons for earthquake damage being more severe than expected in this area are analyzed. It is considered that the reasons for the relatively severe damage is not only relevant to the quality and structure of the building itself, but also to the long period effect caused by the teleseism, the geography influence and the long duration time of seismic wave.