The characteristics of stress distribution has been studied based on the measuring data in Three Gorges Project. There is obvious difference between shallow and deep tectonic stress states

the direction of the maximum horizontal principal stress is NEE at shallow depth

but it is NW at great depth

and is NNE at permanent shiplock at shallow depth. The characteristics of stress distribution in permanent shiplock before and after excavation has been studied. The stress states have been readjusted and distributed before and after excavation in permanent shiplock; the stresses in the EW direction increase or decrease at different altitudes in the slope rockmass; the stress release is smaller. The stresses in the SN direction decrease in middle and upper part in the slope rockmass; stress release is rather large; and there is stress concentration at grading angle part after excavation. The direction of maximum horizontal principal stress rotates in clockwise

change from NE to EW direction with the excavation of permanent shiplock.