We report 2 cases of superficial non-ampullary duodenal tumor resected using laparoscopic endoscopic cooperative surgery( LECS). A man in his5 0's underwent screening esophagogastroduodenoscopy. Endoscopy revealed a 0-Ⅱc lesion at the anal side of the papilla of Vater that measured 5 mm. We performed LECS, and pathologic examination revealed tubular adenoma with no tumor cellsat the edge of the specimen. A man in his 80's underwent screening esophagogastroduodenoscopy. Endoscopy revealed a 0-Ⅱc lesion at the posterior wall above the papilla of Vater that measured 10 mm. The biopsy showed a well-differentiated adenocarcinoma. We performed LECS, and the pathological examination revealed a tubular adenocarcinoma in the mucosal layer with no carcinoma cells at the edge of the specimen. As the treatment strategy for superficial duodenal tumors has not established yet, further accumulation of cases and investigation are necessary.