We measured the bone ingrowth rate on 22 retrieved human cementless porous coated acetabular cups by the help of computer graphics. All the acetabular cups had functioned well, and had had evidence of radiologic bony ingrowth before revising the acetabular cup. The reason for retrieval of the acetabular cups were: one with habitual dislocation, who with stem loosening, and 19 with polyethylene cup wearing. The period from initial surgery to retrieval surgery was 28 months to 108 months(average 56.1 months). All the retrieved porous coated acetabular cups showed macroscophic bony ingrowth, and the ratio of the whole porous surface to bony ingrowth area was showed 1.14% to 92.27% (average 36%).