Objective: To investigate the clinicopathologic characteristics, diagnosis, treatment and prognosis of lymphangioma of duodenum. Methods: One case of lymphangioma at descending duodenum in adult was analyzed by means of gastroscopy and immunohistochemical examination with review of the 1iterature. Results: A 68-year-old female, presenting with abdominal discomfort, was diagnosed as duodenum lymphangioma. There was an irregular milky granular polypoid lesions in descending duodenum by gastroscopy. The pathological diagnosis was irregularly expanded lymphatics within intestinal muscular layer, of which the lumens contained lymph. Immunohistochemically, vascular epithelia were positive for D2-40, negative for CD34. Regular follow-up of patient, and endoscopic morphology did not change significantly after one year. Conclusion: Lymphangioma in descending duodenum is rare in adults. For patients with atypical symptoms of the upper abdomen, duodenal descending lesions should be considered the possibility of lymphangioma, and should be given individual treatment according to different clinical manifestations.