Abstract: The superstructure and foundation (including the pile foundation) and subsoil of buildings are always holistic in their interactions. In order to judge the safety and feasibility of the entire system, the average settlement and difference settlement of buildings must meet the design requirements. Long-term investigations show that the most effective measure is the disposal and adjustment of the bearing stiffness of subsoil as well as the difference settlement control for the pile foundations. Consequently, the concept of generalized composite foundation is discussed. The reasonable determination of the capacity of soil foundations and some methods to disposal and adjust the bearing stiffness of subsoil as well as pile foundations are presented. Especially, the settlement adjustor installed at the top of piles is developed, which solves the question of applications of end-bearing composite foundation. Successful applications of practical projects in situ indicate that the design method of generalized composite foundation and the corresponding settlement adjustor are wide promising.