[Objective] To investigate the effect of total hip arthroplasty (THA) for proximal femoral fracture in ankylosed hip. [Methods] Between June 2013 to May 2017, THA was used to treat 12 patients with proximal femoral fracture in ankylosed hip. There were 10 males and 2 females. The age ranged from 45 to 60 years, with an average age of 51.7 years. The causes of ankylosed hip were secondary ankylosing spondylitis. The duration of hip fusion was 3 to 10 years, with an average of 5.6 years. The causes of the fractures were: 7 cases of falls and 5 cases of traffic accidents. The time from trauma to surgery was 2-7 days, with an average of 2.8 days. [Results] The incision primarily healed in all patients. All of 12 patients were followed up for 2 to 6 years, with an average of 4.6 years. X-ray films at 3 days after operation showed that the fracture was well reduction and the position of prosthesis was good. At the final follow-up, all patients had no pain in the hip and no lameness. The Harris hip score was 85 to 100, with an average of 94.8. At the final follow-up, all fractures had healed. There were none of patients with loosening of the prosthesis, fracture of the prosthesis, osteolysis, displacement of the acetabular cup, and sinking of the femoral stem.[Conclusion] THA was used to treat proximal femoral fracture in ankylosed hip, can achieve satisfactory results and low of complications.