Abstract: The behaviors of composite piled foundation with variable stiffnesses are studied by experiments,such as load– settlement relation,settlement pattern,effect scope,load sharing and interaction between piles and soil.The differential settlement and volume of piles can be reduced efficiently when the raft is piled more in high loading zone and less in low loading zone or no.The general settlement can be satisfied when the average reaction of piles under the raft is lower than the maximum bearing capacity of the single pile.