Objective  To analyze the effect and the key technical points of modified anterolateral approach for total hip arthroplasty in supine position.  Methods  During August 2013 to August 2016, 321 cases(170 males and 151 females) underwent the modified anterolateral approach for total hip  arthroplasty in supine position. The length of incision, intraoperative blood loss, operation time, postoperative ambulation time, claudication rate and trendelenburg positive rate 3 months postoperatively, and complications were recorded and Harris score was adopted for grading the function of the hip joint.  Results   The average length of incision was 8.4 cm (7.0~10.0) cm, the average amount of bleeding was 165 ml (110~300) ml, the average operation time was 40 min (30~50 min) , and the average postoperative ambulation time was 2.5 days (2~5 days). 3 months postoperatively the claudication rate and trendelenburg syndrome with positive rate were 3%, and nobody had dislocation and defective prosthesis position; the follow-up period with a range of 3 months to 3 years revealed that the average Harris score was 94.5 points.   Conclusion  The modified anterolateral approach for total hip arthroplasty in supine position was a good surgical option with merits such as small trauma and quick recovery, suggesting thai is worth for clinical promotion.