Abstract: OBJECTIVE To investigate the correlation of ascites infection and serum procalcitionin in patients with liver cirrhosis so as to provide reference for diagnosis of ascite infection. METHODS From Apr. 2013 to Apr. 2015, totally 50 viral hepatitis patients with bacterial peritonitis caused by ascites infection were chosen as the experiment group and another 50 viral hepatitis patients without ascites infection were chosen as control group. The ascites samples of the experiment group were collected to cultivate and identify the bacteria and drug sensitivity test was conducted. Serum PCT, PMN and WBC were counted. Bacterial positive rate and serum PCT levels and PTC concentration in different times of the ascites were observed. RESULTS Totally 133 strains of pathogens were isolated from ascites samples of the experiment group, including 52 strains of gram-positive bacteria (39.10%), 65 strains of gram-negative bacteria (48.87%), 15 strains of fungi (11.28%) and 1 strain of acid-fast bacillus (0.75%). Levels of PTC, PMN and WBC of the experiment group in the serum were significantil higher than the control group (P<0.05). When serum PCT was higher than 0.5ng/ml, then it can be defined as positive and according to this, the sensitivity of using PCT to diagnose peritonitis was 96.00%. The control group proved to be all negative, With the intervention, ascites infections of the experiment group had improved and PCT level decreased with it. PCT level of the control group did not change significantly. CONCLUSION Serum procalcitonin and ascites infection are positively correlated, and PCT has a high sensitivity for the diagnosis and treatment of ascites due to cirrhosis infected patients with a high clinical reference value. When treating cirrhotic patients with ascites infection, antibiotics should be chosen rationally and bacterial culture and drug sensitivity test should be conducted in time.