ObjectiveTo investigate risk factors of procedure time of endoscopic submucosal dissection (ESD) for treatment of esophageal lesions. MethodsA total of 160 patients with single esophageal lesion who underwent ESD at department of gastroenterology, Beijing Friendship Hospital from January 2015 to October 2017 were enrolled. Medical information including general information (age and gender), and lesion’s characteristics (location, size, gross morphology, pathological type, differentiation degree, and depth of invasion), operators’experience, circumferential resection size, operation and anesthesia time were retrospectively collected. According to the operation time, the cases were divided into the long-term operation group (exceeded 120 min) and the short-time operation group (less than 120 min). The factors affecting the esophageal ESD operation time were analyzed by univariate and multivariate analysis. ResultsAmong the 160 patients, 120 (750%) were men and 40 (250%) were women. The age was 6265±848 years. The median (interquartile range) size of lesion was 170 (100, 265) cm. The median time of ESD was 11354 (8125, 16875) min. Univariate analysis showed that age >65 years, the lesions of type Ⅱa+Ⅱc/Ⅱc, lesion size >2 cm and >1/2 esophageal circumference resection were associated with a longer ESD operation time (P<005), while gender, lesion location, histological type, degree of differentiation, depth of invasion and the operators’ experience were not related to the length of time of ESD procedure (P>005). Multivariate analysis showed that the type Ⅱa+Ⅱc/Ⅱc (OR=247, 95%CI:101-606, P=0047), lesion size>2 cm (OR=341, 95%CI:134-864, P=0010) and > 1/2 esophageal circumference resection (OR=424, 95%CI:162-1111, P=0030) were independent risk factors for the operation time of longer than 120 min. ConclusionType Ⅱa+Ⅱc/Ⅱc lesions, the lesion size >2 cm and the resection area >1/2 esophageal circumference were independent risk factors for a prolonged operation time of esophageal ESD procedure.