It is well known that a large amount of bone ingrowth is needed on the porous coated femoral stem in order a long-term good result in noncemented total hip replacement in order to obtain a long-term good result in noncemented total hip replacement, and for that, absolute stability is very important by firm fixation in the begining stage of operation. The femur neck or metaphyseal fracture in the operation can have bad influence on the stability or firm fixation ant the beginning of the postoperative stage. From the 105 cases of noncement total hip arthroplasty that had been experienced from Jan. 1, 1987 to Dec.31, 1991 at the Orthopedics of Hangang Sacred Heart Hospital, Hallym University, fractures in 8 cases were analysed to study what factors had roled as a risk factor and then The following results were obtained: 1. Age and sex did not role as a risk factor. 2. The implants used in the fracture group were Anatomic type in 4 cases, Harris-Galante type in 3 cases and Bipolar type in one case. 3. The mean distance between the end of the greater trochanter and the rotation center of femoral head prosthesis was-0.5 in the fracture group, and+0.4 in the non-fracture group. 4. The mean height of the calcar femorale was 10.8mm in the fracture group and 10.2mm in the non-fracture group. 5. The osteoporosis by the Singh index showed 2.44 in the fracture group and 2.29 in the non-fracture group, and therefore the difference between them was significant. 6. The stem-metaphyseal ration was 0.52 in the fracture group and 0.43 in the non-fracture group, and therefore the difference between them was signicant.