Abstract: With the 300 measured data obtained from dam site area in Wudongde Hydropower Station Project, supplemented by numerical regression analysis, the geostress distribution of the area was summarized. The results show that the valley section can be divided into stress-release, stress-transition and stress-direction stable zone, and the maximum horizontal principal stress direction in stress-direction stable zone is relatively close to controlling fracture fault near the dam area, which is different from seismic geostress field in near field region. By comparing geostress distribution of Wudongde dam area valley with symmetrical valley, we can find that the dam area valley has similar stress distribution of symmetrical valleys including the high-stress zone of riverbed and the toe area ,and hump-shaped stress distribution characteristics of rock mass near valley slope. Affected by the morphology of Wudongde valley, the high-stress zone of riverbed and the toe area show a symmetry feature, and the high-stress zone is widely distributed on higher side of the mountain slope. At the same time, the tail of the hump-shaped stress curves of the rock mass by the valley is not stable.