In order to investigate the effects of water level variation to bending moment of frame-dock pile, 7 tests of different water level variation were tested, in the condition of keeping with distributed load of 40 KN. Based on the tests, bending moment of the piles were analyzed. Results show that drop of water level influenced the bending moment of the piles more significantly than rising of water level. The bending moment of #D pile increased 22.76 % and it is greatest increasing magnitudes. The minimum increasing magnitude of the bending moment is # C pile. The bending moment of A and B near the slope shoulder decrease with the increases of water level. But it is opposite to D pile which near the slope toe. The bending moment C pile, located in the central, was influenced by the water level variation rarely. All the curves have the approximative trend when water level rises and falls. So water level change does not change the tendency of the curves, but has effect on the size of bending moment.