Abstract: In engineering treatment of soft and weak ground and high rise building foundations, grouting fiction piles are increasingly getting popular. This paper makes theoretical analyses to the bearing mechanism and the load transmitting behavior of these piles in the light of construction cases and in-situ practice. Determination of load transmitting behavior field tests is considered to be more close to the real case than from other methods, although there are some remaining problems from the alteration of modulus of elasticity and pile diameters.