Abstract: Objective To investigate the clinical characteristics of peptic ulcer in young and middle-aged patients and old-aged patients,and to improve the awareness of clinicians.Methods A retrospective analysis was performed in 351 cases(old-aged group) and 351 cases(young and middle-aged group) of peptic ulcer in our hospital from Jan,2012 to Jan,2013.The clinical data were compared between the two groups,including clinical symptoms, complications, ulcer site, size, concomitant diseases, treatment and outcome.Results(1)Clinical symptoms:the symptoms were not typical in old-aged group compared to young and middle-aged group(80.3% vs 73%),complications as the initial symptom was more common(46.7% vs 29.6%,P<0.001), typical upper abdominal pain were lower than those in the young and middle-aged group(19.7% vs 37%,P<0.001);(2) Common complications:old-aged patients with complications was significantly higher than in the young and middle-aged group(46.7% vs 29.6%,P<0.05),in which bleeding,perforation and obstruction were common;(3) Ulcer site:gastric ulcer,elevation ulcer werw more common in old-aged patients than young and middle-aged patients(P<0.05);(4) Ulcer size:giant ulcer(more than 2.0 cm) was more common in old-aged patientsthan young and middle-aged patients(15.1% vs 4.3%,P<0.05);but there was no difference in the infection rate of Helicobacter pylori(HP) between them(90.3% vs 90.9%, P >0.05);(5) Concomitant diseases:the incidence of concomitant diseases was higher in old-aged patients, including diabetes, cardiovascular disease,gallstones, cholecystitis, gout(47% vs 15.7%, P <0.05);(6) Treatment and outcome:the mortality of old-aged patients with complications was significantly higher than those in the young and middle-aged group(14%vs 3.8%,P<0.05).Conclusion The clinical manifestations of peptic ulcer in old-aged patients are atypical,with characteristics of high morbidity, high incidence of complications, high mortality.Early diagnosis and treatment is essential to improve the prognosis and reduce mortality.