Objective To discuss the causes of acute upper gastrointestinal bleeding(AUGB) and the rela-tive factors. Methods Retrospective analysis was performed on the data of 539 cases of AUGB underwent gastroscopy from April 2003 to March 2007. Results The principal causes of AGUB were peptic ulcer,acute gastric mucosal le-sion,esophageal varices,gastric cancer and cardial mucosal fissure. The rate in male was higher than that in female. Peptic ulcer was the first cause of AUGB in all groups. Conclusion The principal causes of AUGB were peptic ul-cer,acute gastric mucosal lesion, esophageal varices, gastric cancer and cardial mucosal fissure. Age and sex were cor-relative with AUGB.