Objective To investigate the procedure of left upper lobe apicoposterior segment resection by single-port thoracosco-py. Methods The clinical data of 23 patients who underwent single-port thoracoscopic resection of the left upper lobe apicoposterior segment in the Department of Thoracic Surgery，the Affiliated Hospital of Southwest Medical University，from January 2020 to June 2021 were retrospectively reviewed. There were 8 males and 15 females，with a median age of 53（34 ~ 67）years. All patients under-went anatomic left upper lobe apicoposterior segment resection through the interlobar fissure approach via the incision in the 5th inter-costal space at the left midaxillary line. Results Thirteen patients with complete interlobar fissure and 10 patients with incomplete inter-lobar fissure underwent the surgery under the single-port thoracoscope，without conversion to multi-port thoracoscopy or thoracotomy. There were a median operative time of 100 min（85 ~ 120 min），a median intraoperative blood loss of 30 mL（10 ~ 50 mL），a median number of required linear cutter stapler places of 5（5 ~ 6），a median postoperative catheterization time of 3 days（2 ~ 5 days），a me-dian postoperative hospital stay of 3 days（2 ~ 7 days），and a median number of resected lymph nodes of 5（3 ~ 6）. There were 2 pa-tients with postoperative complications and no surgery-related death. Conclusion Single-port thoracoscopic resection of the left upper lobe apicoposterior segment is safe and feasible，regardless of complete or incomplete interlobar fissure.