Abstract: ob＜x＞jective To analyze the risk factors of spontaneous bacterial peritonitis (SBP) in patients with cirrhosis and ascites, and establish predictive models. Methods Totally 191 patients with cirrhosis and ascites complicated with SBP were enrolled from January 2014 to December 2018 in Affiliated Hospital of Xuzhou Medical University; 41 patients with SBP were SBP group and 150 patients without SBP were non-SBP group. General patient information, comorbidities, clinical signs and symptoms, and laboratory indicators were collected to screen out relevant influencing factors of SBP. Univariate analysis and Logistic regression analysis were used to screen related risk factors of SBP in patients with cirrhotic ascites, and establish the diagnostic model. The effectiveness of the diagnostic model was verified by the area under the subject operating characteristic curve (AUC). Results Univariate analysis showed that abdominal pain, fever, total serum albumin, serum sodium, red blood cell count, serum-ascites albumin gradient, creatinine, white blood cell count, percentage of neutrophils, ascites white blood cell count and ascites polymorphonuclear percentage ( PMN%) were correlated with SBP in cirrhotic ascites (P < 0. 05). Multivariate analysis showed that fever (OR= 4.282, 95%ci: 1.425~12.870), ascites PMN% (OR= 1.080, 95%ci: 1.053~1.107) were significantly correlated with SBP in patients with cirrhotic ascites (P=0.01, P< 0.001). A diagnostic model was constructed ba＜x＞sed on fever and ascites PMN%. The SBP diagnostic model for cirrhotic ascites was established ba＜x＞sed on the results of multi-factor analysis. The AUC of the model is 0.885, and the optimal cut-off value is 0.309. Conclusion Ascites PMN% and fever are independent risk factors of SBP in patients with cirrhosis and ascites. The diagnostic model established on this basis has a high accuracy rate for predicting SBP in patients with cirrhotic ascites, providing a reference for early clinical diagnostic and treatment of SBP patients in the future.