Abstract: The improvement of the safety factor of the slopes reinforced with piles closely relates to the pile position and head conditions.A series of centrifugal model tests are employed to study the deformation of slopes reinforced with piles.Some conclusions are drawn from the tests:before the slope failure,the head horizontal displacement of the pile set in the middle of the slope is much larger than that in other positions,and under the same failure load,the displacement vectors of the slope reinforced with the piles set in the middle of the slope are larger than those in the toe and shoulder of the slope.It indicates that the reinforced piles set in the middle position and the fixed pile head are more effective to improve the safety factor of the slope.