Model tests on composite foundation of cement-soil pile under cyclic loading were conducted. The vertical additional pressure

stress ratio of pile and soil

the pore water pressure

and the settlement of composite foundation of cement-soil pile

etc. were discussed. The test results show that (1) the saturated soft foundation improved with cement-soil piles occurred redistribution of stresses; (2) the effects of cyclic stress ratio

number of loading cycle and replacement ratio on the stress ratio of pile to soil of composite foundation were remarkable; (3) the saturated soft foundation improved with cement-soil piles decreased the pore water pressure value and the settlement of back work; (4) the vertical deformation of the top of piles and pile-surrounding soil is not coordinative. The permanent settlement of the pile top piles is less than that of pile-surrounding soil; and this tendency is more remarkable with increasing number of loading cycle.