Upper gastrointestinal bleeding is a common cause of death, especially when it involving large vessels or patients with severe organ dysfunction. Early evaluation should be initiated for patients with or suspected with acute upper gastrointestinal bleeding. Unstable patients should be treated with fluid resuscitation and empirical therapy under airway protection, followed with re-evaluation, adjustment of therapy and evaluation after treatment. The aim of this paper is to provide a clinical thinking and a management procedure for emergency doctors.