This paper carried out a study of stress sensitivity evaluation on clay shale and sandstone reservoirs of Yanchang Group in Ordos Basin and compared the differences of stress sensitivity. The results showed that: shale has strong stress sensitivity; silty sandstone has medium-partial strong stress sensitivity; tight sandstone has a weak stress sensitivity; under the effective stress of 30 MPa, the rock presents plastic deformation. Therefore, for different lithologic reservoirs, reasonable production pressure difference should be adopted to avoid the occurrence of reservoir stress sensitivity damage.