The successful fixation of a porous coated arthroplasty is dependent, first, on the initial stabilization produced by the surgeon in the operating room and, second, on the biologic fixation that occurs over time. In AML, the success of initial stabilization can be graded by the intraoperative initial 6 poirit fixation and by postoperative bone ingrowth. We have experienced 85 cases of AML hip arthroplasty and followed up more than 24 months from Nov. 1984. to Aug. 1990. The results were as follows; 1. Preoperative average Harris hip score of 41.4 point became 86.3 point postoperatively average 34 months follow up, and the improvement of score was much more at relatively younger group. 2. Mode of fixation were bone ingrowth in 59 hips (69%), stable fibrous ingrowth in 21 (25%) and unstable implant in 5 (6%). 3. The press fit of the stem at the isthmus on immediate postoperative anteroposterior radiograph was observed in 54 hips (63%), they were achieved more Harris hip score (90) and more stable fixation in 51 hips (94%). 4. There was pain on thigh in 6 cases (7.1%) above 2 years, and 5 out of these 6 cases developed unstable fixation. 5. The average vertical subsidence was 2.5mm, 1.8mm in press fit, and 2.9mm in no press fit. There were 6 cases (7.1%) of vertical subsidence more than 5mm, Harris hip score was lower. 6. There were 51 cases (60.0%) of stress shield on proximal femur, below 12mm of stem size (14/36 cases) were 39%, above 13.5mm of stem size (37/49 cases) were 76%. As a conclusion of study, AML hip replacement was achieved more better clinical results in younger group. If the initial stability was achieved by intraoperative press fit fixation, more better stable fixation.