Objective To evaluate the efficacy of submucosal tunnel endoscopic resection (STER) for upper esophagus submucosal tumors (SMT) originating from muscularis propria (MP) layer and the influencing factors.Methods Retrospectively analyzed the clinical data of 41 cases of upper esophagus SMT originating from MP layer treated with STER.Results The lesion was located 22.0 (20.0, 23.0) cm from the incisor and the length diameter was 1.5 (1.2, 3.0) cm. 15 cases (36.6%) underwent the long tunnel STER (tunnel length ≥ 3.0 cm), and 26 cases (63.4%) underwent the short tunnel STER (tunnel length < 3.0 cm). The operation time was 60.0 (34.0, 93.0) min, and the en bloc resection rate was 80.5% (33/41). There were 3 cases (7.3%) of intraoperative complications, including 2 cases (4.9%) of tunnel mucosal injury and 1 case (2.4%) of major bleeding. There were 4 cases (9.8%) of postoperative subcutaneous emphysema, 3 case (7.3%) of hyperthermia, all of which recovered through conservative treatment, and the postoperative hospital stay was 6.0 (4.5, 7.0) d. The operative time (P = 0.000) in the tumor length diameter ≥ 3.0 cm group was longer than that in the tumor length diameter < 3.0 cm group, the postoperative complications (P = 0.014) was more than that in the tumor length diameter < 3.0 cm group, and the en bloc whole resection rate (P = 0.036) in the tumor length diameter ≥ 3.0 cm group was lower than that in the tumor length diameter < 3.0 cm group. The difference of tumor size, tumor shape, operative time, intraoperative complications, en bloc resection rate, postoperative complications and postoperative hospital stay between the long tunnel STER group and short tunnel STER group were not statistically significant (P > 0.05). Pathology was diagnosed as leiomyomas in 39 cases and schwannomas in 2 cases. There was no tumor recurrence at the postoperative follow-up (34.2 ± 18.7) months, and no esophageal stricture occurred.Conclusion STER is safe and effective in treating upper esophagus SMT originating from MP layer without serious complications, especially for SMT with a length diameter < 3.0 cm. The safety and efficacy of short-tunnel STER for upper esophagus SMT have also been initially confirmed.