Abstract:[Objective] To introduce the surgical technique and preliminary results of replacement with a mass autograft of palmaris lon- gus tendon for defect secondary to lunate resection for avascular necrosis of the lunate. [Methods] From May 2019 to May 2022, 8 patients underwent lunate resection and replacement with mass autograft of palmaris longus tendon for avascular necrosis of the lunate. After a carpal arc-shaped incision was made, the necrotic lunate was exposed and removed completely. The palmaris longus tendon was harvested and pre- pared to a mass graft, and then implanted into the defect. [Results] All the 8 patients had operation performed successfully without serious complications,and were followed up for more than 12 months. The VAS score significantly decreased from (5.5±0.9) before surgery to (0.3± 0.4) at the last follow-up, with a significantly improvement in wrist range of motion postoperatively. In addition, the muscle strength of wrist and finger improved by 1~2 degrees at the latest follow up compared with those before operation. The Mayo score was (91.1±3.3) at the last follow-up, with the excellent and good rate of 100%. In term of imaging examination, there was no displacement of carpal bones with normal arrangement of the structures till the latest follow up. [Conclusion] This mass autograft of palmaris longus tendon might replace the support- ing function of lunate, has benefits of simple operation, and does achieve satisfactory preliminary results.