Abstract: Concrete-cored sand-gravel pile as a new technique for improvement of soft foundation is briefly introduced.Based on the squeezing effect in the process of pile sinking,the squeezing behaviour of concrete-cored sand-gravel piles is analyzed by applying cavity expansion theory and consolidation theory.Results of calculation show that dissipation of excess pore water pressure due to squeezing effect of concrete-cored sand-gravel piles is faster than that of the ordinary CFG piles.