Adenocancer of proximal jejunum is rare disease, and in Korea there is seldom case report of this disease yet. The patient is 57 year old Korean female with complaint of nausea and vomiting for about 10 days. Routine upper gastrointestinal series show localized short segment of marked narrowing with irregular mucosal destruction in proximal jejunum beginning to ligament of Treitz. (about 7cm. in length) Operation was done and confirmed as adenocancer of proximal jejunum by biopsy.