Abstract: The topography and geomorphology of which surrounded by mountains is the material sources of mixed soils in Caracas,Venezuela.The project in this paper is located in Caracas with the mixed soils that contain sand,gravel,silt and silty clay.And the mixed soils with lower bearing capacity is unhomogeneous which represented by discrete SPT blow counts.Through the PLTs on nature ground and pure-concrete-pile composite ground,this paper indicates that the beating capacity of the mixed soils is more increased by ground improvement.And feasible construction technology of pure-concrete-pile is also tested.The application of pure-concrete-pile composite ground in Caracas mixed soil is successful and perfect.