Abstract: Objective　To investigate the related risk factors of complicated parapneumonic effusion (CPPE) in children. Method　The clinical data of 88 children with parapneumonic effusion (PPE) were retrospectively analyzed from January 2013 to April 2015. According to the treatment effect of antibiotics, CPPE group and uncomplicated parapneumonic effusion (UPPE) group were divided. The univariate analysis of clinical and laboratory parameters was performed between two groups. Then the multifactor logistic regression was performed further. The receiver operator characteristic (ROC) curve was draw. Results The univariate analysis indicated that the risk factors were the formation of loculation and serum CD3+ and CD19+ levels (Z=2.030~7.457, P<0.05). The multifactor logistic regression showed that the formation of loculation（OR=3.386, P=0.018） and serum CD19+ levels （OR=4.000, P=0.009）were independent risk factors of CPPE. The area under the ROC curve (AUC) is 0.707, which indicated that the regression model had medium diagnostic accuracy (P=0.001). Conclusion　CPPE may be developed in PPE children with the serum level of CD19+ >30% and the formation of loculation.