Objective:To analyze the causes of early dislocation after total hip replacement and explore its preventions and treatments. Methods:From July 1997 to October 2002, there were 12 cases of dislocation after total hip replacement. The strength of their hip abductor was tested and the X-ray films were measured. If closed reduction failed, capsular repairing was used. Results:There were 3 cases of malposition, 5 cases of abnormal soft-tissue tension, 3 cases of malposition and abnormal soft-tissue tension and 1 case of over motion. Close reduction was succeeded in 5 cases, 7 cases failed to close reduction, and were treated successfully by repairing the hip capsule and readjusted the prostheses when necessary. Conclusion:Abnormal soft-tissue tension has become the main causes of dislocation after total hip replacement. Those cases in which closed reduction has failed can be treated by repairing the hip capsule.