To investigate the clinical efficacy of extended thymectomy by subxiphoid approach video-assisted thoracoscopic surgery(VATS) for myasthenia gravis. Methods We retrospectively analyzed the clinical date of 64 cases of myasthenia gravis treated by subxiphoid approach VATS in the same surgical team from September 2015 to April 2018. The patients were equally divided into 4 groups(A, B, C and D) according to the date of operation. Comparisons were made among the four groups in operation time, blood loss during operation, rate of conversion to thoracotomy, postoperative complications, postoperative hospital stay, duration and amount of postoperative chest tube drainage, frequenlly of surgery. The operative effect of different stage was analyzed. Results There were no intraoperative deaths. 1 patient(group A) was converted to thoracotomy. 3 patients(2 cases of group A; 1 case of group D) had lung infection. 1 patient(group B) developed myasthenia crisis after surgery, and the rest patients showed obvious improvement in postoperative myasthenia symptoms. No significant differences were found in postoperative complications, rate of conversion to thoracotomy, postoperative hospital stay, duration and amount of postoperative chest tube drainage among the 4 groups(P >0. 05). The operation time was significantly longer in group A(186. 25 ± 25. 79) min than the other 3 groups [B(128. 75 ± 16. 28) min, C(135. 00 ± 21. 29) min, D(128. 75 ± 19. 62)min], P <0. 05. The blood loss in surgery was significsntly more in group A(110. 00 ±38. 82)ml than that in the other 3 groups[B(63. 75 ±28. 26)ml, C(58. 13 ±27. 86)ml, D(58. 75 ±25. 00)ml], P <0. 05, while no statistical difference was found among group B, C and D. The frequency of surgery was increased from 1. 6 cases in group A to 2. 3, 2. 7 and 2. 7 cases one month in B, C and D, respectively. Conclusion The results of the present study have shown that subxiphoid approach VATS thymectomy is safe and feasible for the treatment of MG patients. For thoracic surgeons with certain experience in thoracoscopic technique, a plateau of the surgical skill of the subxiphoid opproach can be reached after learning curve procedures.