To compare the cl inical effect of total hi p arthroplasty (THA) using posterolateral conventional or minimally invasive incision. Methods From January 2007 to November 2007, 38 patients (41 hi ps) were treated with minimally invasive THA (mini-incision group), and 15 patients (15 hi ps) underwent conventional THA (conventional incision group). Mini-incision group: 23 males (25 hi ps) and 15 females (16 hi ps) aged (53.2 ± 15.5) years old; body mass index (BMI) was 23.4 ± 3.3; there were 20 cases (20 hips) of femoral neck fracture, 2 cases (2 hips) of primary osteoarthritis, 14 cases (16 hips) of stage III or IV aseptic necrosis of the femoral head, 2 cases (3 hips) of ankylosing spondyl itis involving hip joint; Harris hip score was 47.7 ± 5.5 and the course of disease was (4.5 ± 4.3) years. Conventional incision group: 7 males (7 hips) and 8 females (8 hips) aged (54.8 ± 10.8) years old; BMI was 26.1 ± 5.1; there were 8 cases (8 hips) of femoralneck fracture, 1 case (1 hip) of primary osteoarthritis, 5 cases (5 hips) of stage III or IV aseptic necrosis of the femoral head, 1 case (1 hip) of ankylosing spondyl itis involving hip joint; Harris hip score was 51.2 ± 4.3 and the course of disease was (3.8 ± 3.7) years. There were no statistically significant differences between two groups in the general information (P gt; 0.05). Results There were statistical differences between two groups in terms of incision length, perioperative blood loss, drainage volume and blood transfusion volume (P lt; 0.05), and no statistical differences were evident in operative time, abduction angle and the anteversion angle of acetabular cup (P gt; 0.05). All incisions healed by first intention and no early postoperative compl ications occurred. Two groups were followed for 12-22 months (average 18.3 months). All patients walked without the crutch at 2-3 months after operation. The Harris score of the mini-incision group and the conventional incision group 6 months after operation was 88.6 ± 3.6 and 85.8 ± 3.3, respectively, indicating there was no significant difference between two groups (P gt; 0.05), but there was significant difference between before and after operation (P lt; 0.05). Conclusion Compared with conventional THA, the minimaly incisive using posteroplateral approach THA has the merits of mini invasion, sl ight hemorrage, short hospital stay, minor compl ication, convenient management of femoral head and accurate prosthesis location. However, strict attention should be paid to operative indications.