Objective To investigate the endoscopic ultrasonography manifestations and endoscopic treatment of gastrointestinal neuroendocrine neoplasms(GI-NENs). Methods 27 cases of GI-NENs treated endoscopically in the First Affiliated Hospital of Xi"an Jiaotong University were Included in the study. The clinical features, endoscopic ultrasonography manifestations, pathological characteristics and endoscopic treatment effect were retrospectively analyzed. Results 27 cases of GI-NENs showed submucosal bulging under endoscopy. The length was (0.69±0.44) cm (0.32-2.00 cm) by endoscopic ultrasonography (EUS). 14 cases (51.9%) derived from submucosa, 8 cases (29.6%) of mucosal muscle and 5 cases (18.5%) of mucosal. The diagnostic accuracy of EUS was 92.0%. 6 cases were treated by endoscopic mucosal resection (EMR), while 21 cases were treated by endoscopic submucosal dissection (ESD). The incidence of bleeding after ESD was 4.8%. The pathology was 20 cases (74.1%) of G1 grade, 6 cases (22.2%) of G2 grade, 1 case (3.7%) of G3 grade with lymphatic tumor thrombus. The overall survival rate was 96.3% during 3-36 months of follow-up. For patients with G1 and G2 neuroendocrine tumors limited to submucosa without vascular invasion, the recurrence rate of EMR was higher than that of ESD (33.3% vs 0%, P = 0.042), while there survival rate did not significantly differ. Besides, there was no significant difference in complications of bleeding, perforation between patients recieved EMR and ESD. Conclusion Endoscopic ultrasonography can be used for preoperative diagnosis of GI-NENs. The recurrence rate of ESD was lower than that of EMR in G1 and G2 grade GI-NENs that limited to submucosa, within 2 cm with no vessel infiltration.