Abstract: Objective To evaluate the effect and outcome of endoscopic submucosal dissection(ESD) in the diagnosis and treatment of early gastrointestinal precancerous lesions. Methods From 2013 to 2016,62 cases of suspected gastrointestinal cancer patients in our hospital were enrolled into the study,including 41 cases of male and 21 cases of female.The average age was (58.5±6.2) years.All patients were diagnosed and treated by ESD,which were confirmed by pathological findings as early precancerous lesions.The effect of ESD in the diagnosis and treatment was evaluated;the complications and prognosis of patients were observed. Results The lesions were all located in the mucosa and submucosa.The lesions were located in esophagus(17 cases,27.42%),stomach(29 cases,46.77%) and colon(16 cases,25.81%),respectively.Most of them were middle esophagus(10 cases,58.82%).The pathological type Ⅰ was 4.84%(n=3) and type Ⅱ was 95.16%(n=59),in most of the patients it was of Ⅱb(28 cases,45.16%).The total resection rate was 95.16%(59/62),and the cure rate was 90.32%(56/62).The incidence of the complications was bleeding in 1 case(1.61%),perforation in 2 cases(3.23%),postoperative chest pain in 2 cases(3.23%),abdominal pain in 1 case(1.61%),they were all cured after anti-infection and antacid treatment.The sixth months follow-up showed that there was no lost patients,the patients with eating discomfort and dysphagia symptoms were obviously relieved(21 cases,33.87%;18 cases,29.03% respectively).Recurrence was found in 1 case(1.61%),and was cured after ESD. Conclusion ESD is effective in the diagnosis and treatment of early gastric precancerous lesions,with the low incidence of the complications and postoperative recurrence rate.It can be used as the first choice for minimally invasive diagnosis and treatment of precancerous lesions of digestive tract.