Abstract: Objective To explore the value of macrophage migration inhibitory factor(MIF) in predicting the occurrence and adverse prognosis of sepsis complicated with acute renal injury(AKI).Methods A total of 139 septic patients admitted to ICU were examined.They were divided into two groups of AKI and non-AKI according to whether or not there was a complication of AKI.The influencing factors of septic AKI were analyzed by regression and the impact of MIF on adverse prognosis of septic AKI analyzed by Kaplan-Meier survival and Cox regression.Results A total of 71 pathogenic microorganisms were identified,including 40 strains of gram-negative(G^-) bacteria(56.34%),27 strains of gram-positive(G⁺) bacteria(38.03%) and 4 strains of fungi(5.63%).Binary Logistic regression analysis revealed that hypertension,sequential organ failure assessment(SOFA) score,acute physiology & chronic health evaluation(APACHE II) score and MIF were independent influencing factors of sepsis plus AKI.Odds ratio(OR) was 4.918,2.620,1.957 and 2.832 respectively and albumin(Alb) was a protective factor of sepsis plus AKI with an OR value of 0.802.The area under the curves(AUC) of MIF,cystatin C(Cys C) and Alb for predicting septic AKI were 0.744,0.740 and 0.700 respectively.MIF in AKI 3 was significantly higher than AKI 1(P＜0.05),AUC of MIF for predicting adverse prognosis of AKI was 0.704 with an optimal cutoff value of 6.10 μg/L.Sum survival rate of high MIF group(MIF≥6.10 μg/L) was lower than that of low MIF group(MIF＜6.10 μg/L).Cox survival analysis indicated that,for each 1 μg/L rise in MIF,risk of mortality spiked by 1.522 folds.Conclusion Serum MIF may be a potential biomarker of predicting the occurrence,progression and prognosis of septic AKI.