Abstract: To mobilize the bearing capacity of subsoil sufficiently, the long-short composite piled raft foundation with cushion was applied in a 14 - storeyed high-rise building. The load sharing among piles and soil as well as the settlement of foundation varied with change of superstructure loads were observed in construction and in the early service. The behavior of this composite foundation including load-settlement relations, loads sharing characters and interaction mechanism of piles and soil were analyzed in detail. The conclusions of this paper were useful for further theoretical studies and engineering design.