Abstract: In the pile foundation engineering, the analysis of laterally loaded pile-soil interaction is confined to elastic pile and nonlinear soil for a long time.In this paper a space coupling numerical model for pile-soil system with nonlinear damage of reinforced concrete is established. The feasibility and rationality of this approach are proved by an example. The reduction of pile stiffness caused by concrete damage and increment of lateral displacement produced by softening of soil near pile can be simultaneously computed in this approach. Its physical meaning and mechanism are clearer than that of conventional approaches existing before.