To investigate the cyclic lateral response characteristics of bridge pile foundations in sloping ground， model experiments of piles in sloping ground under different cycle numbers，load amplitudes and slope angles were carried out. The accuracy of measurement results was validated by the comparisons between the measured subgrade reaction profiles and those derived by measured bending moment profiles，and then the evolutions of pile head de? flection，rotation at the pile head，bending moment and subgrade reaction profiles were revealed. The measurement results show that the pile head deflection is composed of elastic deformation and plastic deformation，in which the elastic deformation almost remains unchanged and the plastic deformation nonlinearly increases with cycle numbers at a decreasing rate，that is the plastic shakedown. The dimensionless pile head deflection and rotation atop the pile nonlinearly increase with cycle numbers，and the upper envelopes of the former can be fitted by power functions y0/D =An0.11. The one-way cyclic lateral responses of piles in sloping ground are mainly affected by the first 100 cyclic lateral loadings. The maximum bending moment and subgrade reaction increase with the load amplitude and slope angle，and their locations fall with the increase of slope angle but are rarely affected by the load amplitude.