Abstract: [Abstract] Objective：To evaluate the efficacy of total hip replacement（THA）in the treatment of developmental dysplasia of hip（DDH）associated with osteoarthritis in adults.Methods：THA was used to treat 28 adult DDH patients with 30 hips，among them，Crowe Ⅰ type 4 hips，Crowe type Ⅱ10 hips，Crowe type Ⅲ 8 hips，Crowe type Ⅳ 8 hips，the modified posterolateral，intraoperative periprosthetic soft tissue release，restore the true acetabular reconstruction，prolong objective limb length.Follow up was 6 to 60 months，with an average of 33 months.Harris scoring system（including pain，function，etc.）was used for preoperative and postoperative follow up.Results：Preoperative Harris score of 23～57 points，with an average of（42.37±2.51）points，postoperative score of 79～95 points，with an average of（88.13±3.27）points，significantly improved than before（P＜0.05）.The pain was relieved，the activity and function were satisfactory，the quality of life was greatly improved，and the prosthesis position was better and no looseness occurred.Conclusion：THA is an effective method in the treatment of adult DDH，which can greatly relieve the pain and improve the function of the patients.

Key words: developmental dysplasia of the hiptotal hip arthroplasty；true mortar reconstruction  ,