Background : Endoscopic triamcinolone injection (ETI) post-esophageal endoscopic submucosal dissection (ESD) have been reported to be effective for prevention of stricture. But the appropriate method of injection, how many sessions should be performed, the proper concentration of triamcinolone suspension, the proper dosage of one injection, is remained unclear. Aim : Only one session of ETI performed immediately after ESD was reported to be effective for prevention of post-ESD esophageal narrowing4,5) , but had a few complications. To establish the safer and more effective and efficient method of ETI, we estimated the feasibility of our institute′s ETI method described below. Method : 7 patients of superficial esophageal squamous cell carcinoma treated with semi-circumferential (more than three fourths of the lumen) ESD in Showa General Hospital from May 2011 to August 2012 were evaluated. A number of sessions of ETI were restricted to two sessions, immediately after ESD and one week after. The triamcinolone suspension was adjusted to 13-20mg/ml concentration. Each 0.1-0.3ml of this suspension was injected into submucosa of the periphery and the base of post-ESD ulcer at 1cm-1.5cm intervals. 6 weeks after the process, esophagogastroduodenoscopy was performed and examined the incidence of esophageal stricture and the necessity of endoscopic balloon dilatation (EBD) . Results : Esophageal stricture was not found on endoscopy at 6 weeks after the second session of triamcinolone injection in all patients, and no patients complained of dysphagia and required EBD. There were no complications associated with this method, no perforations nor systemic side effects. Conclusions : This study suggests that two sessions of triamcinolone injection method is safe and effective for prevention of esophageal stricture after semi-circumferential ESD. But it is indispensable to acquire the skill and the few arts of endoscopic manipulations for safe and effective ETI. This method is suggested to be an effective strategy, but further study in a larger subject is required.