The western part of Loess Plateau area is one of most seismically active areas in China. 650 large scale landslides were triggered by the earthquake of Haiyuan (Dec. 16. 1920, M=8.5) in Ningxua Province, China.
In this paper, the characteristics of these landslides are discussed in terms of the equivalent coefficient of friction and the slope angle of the source areas of landslides.
1) The ratio of the volume of landslides induced by the Haiyuan earthquake to the equivalent coefficient of friction was rather small compared with other landslides.
2) Large scale landslides induced by the Haiyuan earthquake occurred on the loess slopes having slope angles of less than 15°.
These phenomena represent that the occurrence of landslides were due to excess pore water pressure generation or liquefaction caused by the earthquake.