Abstract: Objective To report the preliminary curative effect of overturned sartorius iliac flap in repair of acetabular defect in developmental hip dislocation（DHD）. Methods Eighteen patients（20 hips） with severe acetabular defect in DHD were treated with open reduction of joint capsule,shortening and fixation of proximal femur tuberosity with steel plates,and overturned sartorius iliac flap.The lower extremities were fixed with plaster for 45 days after operation.The clinical outcomes were assessed according to the McKay functional and Severin radiograph standards,respectively. Results Sixteen female patients（18 hips） aged 4-13 years（mean 6.1 years） were followed up for 4-37 months（mean 22.8 months）.The excellent rate was 89% according to the McKay functional and Severin radiograph standards. Conclusion The overturned sartorius iliac flap can effectively promote bone healing and repair acetabular defect in severe DDH.