Abstract：Considering the limited knowledge on the liquefaction behaviors in the Wenchuan 8.0 earthquake，the liquefaction characteristics are discussed through detailed site investigation and analyses of corresponding hydrological，geologic and in-situ tests for the specific sites. The analytical results indicate that the distribution of the liquefaction phenomena in the event is vast with the region covered by length of 500 km and width of 200 km，but the liquefaction distribution is rather nonuniform. The liquefaction is mainly located in the area of a rectangle with 160 km in length and 60 km in width；and it is distributed principally in the 6 belts，which are consistent with the local hydrological and geotechnical conditions. Moreover，three salient characteristics of the liquefaction behaviors that are different from the previous earthquakes are discovered by the investigation. It is shown that：(1) Liquefaction phenomena are observed within the regions of seismic zone with intensity VI，which has not been documented previously in Mainland of China. 10 such liquefaction sites in 5 different areas are confirmed and in 2 liquefaction sites among which the buildings are damaged directly due to the liquefaction. (2) The liquefaction phenomena in deep soils，i.e. more than 20 m in depth，occur in the shock，and the macrophenomena of more than 10 m water ejection in 4 different villages are observed；and the in-situ tests for the specific sites verify the judgment. (3) The characteristics show that the gravel soils liquefy in the shock；and the in-situ tests for the specific sites verify the reality of such behaviors. Also the synthetic analyses of sand ejection，duration of waterspout and corresponding geotechnical information all demonstrate that the gravel soil liquefaction behaviors are considerable in this earthquake.
