Abstract: The paper does some researches on stress field distribution characteristics of the valley in high geostress areas by using numerical simulation and in-situ stress measured data. The result shows that: for the maximum principal stress , the homogeneous elastic slope without unloading zone could be classified into two zones as the stress-releasing zone ( ) and the stress-stable zone ( ) from the slope surface to the inside, where h stands for the original buried depth of the studied point, while there are three zones classified for the homogeneous elastic slope with unloading zone as the stress-releasing zone ( ), the stress-concentrating zone ( ) and the stress-stable zone ( ). The existence of unloading zones is the essential reason for the maximum principal stress existing three zones from the surface to the inside. Due to the existence of the tectonic stress field, the slopes in high geostress areas enhance the stress concentration significantly, extend the concentrating scope obviously and present wide unloading zones generally. Therefore, the stress field of the high and steep slope in high geostress area could be approximately classified into three zones: the stress-releasing zone, the stress-concentrating zone and the stress-stable zone. While the stress concentrating zone of the slopes which possess deep unloading transfers into the inside. The stress of the stress-releasing zone fluctuates and the stress decreases in the zone possessing the deep cracks

Key words: valley slope, stress field, unloading zone