Abstract: Objective To investigate the value of narrow band imaging in the diagnosis for multiple primary cancer of upper gastrointestinal tract. Methods From June 2010 to June 2011,2 452 patients underwent upper gastrointestinal endoscopy were enrolled into this study.The suspected lesions were screened with both white light and narrow band imaging(NBI)system,and the superficial glandular structure and microvascular pattern were observed by using magnifying endoscopy with NBI.The T staging of carcinoma diagnosed by biopsy sample was evaluated by endoscopic ultrasound,abdominal CT or surgical resection specimen. Results Thirteen patients(0.53%)had synchronous multiple cancers.Of these 13 cases,4(30.8%)had early cancer,including 2 carcinoma in situ of the esophagus and 2 intramucosal gastric carcinoma. Conclusion Early cancer is not rare in multiple primary cancer of upper gastrointestinal tract,and it is difficult to detect the lesion by using conventional white light endoscopy.NBI can improve the diagnostic yield.