Abstract: The peoples resettlement project is a key part of the Three Gorges Project on the Yangtze River. The geological problem in the new town of Wushan County is a current focus of attention and contention in scientific circle, and is also a generally concerned problem in the Three Gorges Reservoir region. In the paper a mechanism for occurrence of landslides is proposed. It shows that the landslide underwent the former slide stage and the latter reworking stage. This mechanism provides a theoretical basis for solution of a great deal of problems in the Three Gorges Reservoir region.