Gastrointestinal tumor could be aggressive and life threaten if it was not be diagnosed and treated at early stage. Digestive endoscopy plays a very important role in the early diagnosis and treatment of gastrointestinal tumor, and shows rapid evolution with novel technologies in the past years, such as endoscopic ultrasonography, magnifying endoscopy, electronic staining endoscopy, endoscopic confocal laser microscopy. Nowaday it becomes feasible to learn more about the endoscopic manifestation in early stage GI tumor. Besides, several new endoscopic surgical techniques, such as endoscopic submucosal dissection (ESD), endoscopicsubmucosal tunnel dissection (ESTD), submucosal tunneling endoscopic resection （STER），has been applied in clinical treatment of early stage GI tumor with curative effect. However, there are some new problems emerged, such as how to determine the depth of the lesion, how to avoid or reduce the incidence of postoperative complications, and how to standardize the pathological classification and the treatment of positive margin, which need multidisciplinary solution with the efforts from endoscopist, clinician and pathologist. With the deep insight on, molecular pathogenesis of GI tumor, new technologies combinding endoscopy, imaging and pathological measures, will promote more GI tumor early diagnosed and effectively treated, thus improve the survival and prognosis of GI tumor patients.
