【Abstract】 Objective To analyze the associated risk factors of early surgical site infection (SSI) in patients undergoing posterior lumbar interbody fusion (PLIF), providing references for reduce the incidence of postoperative SSI. Methods This article analyzes retrospectively 373 cases of posterior lumbar interbody fusion (PLIF) in the hospital from January 2014 to January 2017. We collected the clinical data of patients, then divided them into infection group (group A) and non infection group (group B) according to the results of postoperative blood culture and MRI. Results The overall rate of early SSI was 294% (11/373). The infection rate increased significantly in patients with these characters, such as age 60 and older, smoking history, complicated with diabetes, operation time more than 180 min, and blood loss over 300ml (P＜005). There were no significant difference on gender and drain time of the two groups (P＞005). The age, smoking history, history of diabetes, time of operation, intraoperative blood loss were analyzed with multivariate analysis by nonconditional Logistic regression analysis. The results show that smoking history, history of diabetes, time of operation are independent risk factors of PLIF(P＜005). In contrast, age and intraoperative blood loss have little to do with PLIF(P＞005). Conclusion The retrospective analysis shows that smoking history, history of diabetes, time of operation are independent risk factors of PLIF. The clinicians should focus primarily on these high risk groups, to prevent early infection.