Abstract: Obiective To determine the prevalence of small intestinal bacterial overgrowth（SIBO） in cirrhotic patients，and its correlation to severity of cirrhosis. Methods 47 patients with cirrhosis were selected as observation group，and 15 healthy volunteers were selected as control group. The gastrointestinal symptom of patients were evaluated by a guidance for clinical rational. The data were statistical analysis using SPSS17.0. Results In 47 patients with liver cirrhosis，22 patients（46.8%） were SIBO positive.While in 15 healthy persons in control group，only 1 case（6.6%，P<0.01） was SIBO positive；the LHBT level in patients with cirrhosis was （157.81±98.32） ppm，significantly higher than in the control group[（38.87±16.05） ppm，P＜0.01]，serum bilirubin levels were（93.31±55.15） μmol/L，significantly higher than that in the control group[（14.78±8.12） μmol/L，P＜0.01]，plasma albumin were（31.74±10.37） g/L，significantly lower than that in the control group [（43.90±7.63） g/L，P＜0.01]，globulin were（39.09±5.07） g/L，higher than that in the control group[（35.94±2.31） g/L，P＞0.05]，procalcitonin were（0.10±0.07） ng/ml，significantly higher than that in the control group[（0.03±0.01） ng/ml，P＜0.01]；plasma procalcitonin，bilirubin，globulin and albumin were respectively correlated to SIBO（r=0.895，P＜0.005；r=0.907，P＜0.005；r=0.755，P＜0.005；r=-0.810，P＜0.005）. Conclusions SIBO is prevalent in patients with liver cirrhosis. The cirrhotic patients with SIBO are more easily bloating and loss of appetite.

Key words: Liver cirrhosis, Small intestinal bacteria overgrowth, Hydrogen breath set-value, Gastrointestinal symptom rating scale.