Objective:To compare the pulmonary function after this two kind of operation under video-assisted thoracoscopic surgery (VATS),segmentectomy and lobectomy,on the treatment of small pulmonary nodule (the diameter ≤3cm). Methods:From Nov. 2010 to Mar.2012,15patients underwent VATS segmentectomy and 20 underwent VATS lobectomy.The preoperative and postoperative pulmonary function at six months,included FEV1%,FVC%,MVV%,was compared between the two groups. Results:The postoperative FEV1% was better in segmentectomy group(84.53% ± 13.43) than that in lobectomy group(76.19% ± 8.51%)(P < 0.05). There were no significant differences on the postoperative FVC% and MVV% between the two groups. No death and local recurrence occurred in two groups up to now. Conclusion:On the treatment of small pulmonary nodule (the diameter ≤3cm) under VATS,segmentectomy,whereas the resection of less than three segments,can provide more benefits than lobectomy on preserving pulmonary function.