This paper describes the application situations of DJM in China,including ： the de?velopmental situations of this tech. in China ； cffects of DJM piles (DJMP) ； the soil suitable for the application of DJM 5the behaviour of different materials mixed with the soil 5merits of DJM tech. ,etc. As for some theoretical problems of composite foundation design of DJMP， the author puts forward his views from the viewpoint of theory and practice.