—In the designing of the flexible fender pile,M-method is usually adopted.But M-method isusable only in the case that the value of the force(moment M and shear force Q)exerted on the pile abovethe soil is known.In practical cases,only the percussive energy of the ship can be found,while the exactvalue of the percussive force cannot be computed directly.In this paper,a method is introduced which canbe used to calculate the inner force of flexible fender piles by a computer in these cases.First,according tothe known docking dynamic energy of a ship,the absorbed energy can be found from the deformation ofthe pile and the rubber fender respectively,at the same time the value of the force acting on the fender pilesand the reaction of fenders can be calculated.Then the inner force and displacement of the fender piles canalso be calculated further by M-method.The whole computing process is realized by a computer programand the results obtained are reasonable.In this paper,the computation,the iteration method a -In the designing of the flexible fender pile, M-method is often used.But M-method isusable only in the case that the value of the force (moment M and shear force Q) exerted on the pile abovethe soil is known. practical cases, only the percussive energy of the ship can be found, while the exactvalue of the percussive force can not be computedComponent .In this paper, a method is introduced which canbe used to calculate the inner force of flexible fender piles by a computer in these cases. First, according tothe known docking dynamic energy of a ship, the absorbed energy can be found from the deformation of the pile and the rubber fender respectively, at the same time the value of the force acting on the fender piles and the reaction of fenders can be calculated.Then the inner force and displacement of the fender piles canalso be calculated further by M-method. the whole computing process is realized by a computer programand the results obtained are reasonable.In this paper, the computation, th e iteration method a