Objective To analyze the correlation between serum micrornA-146A (miR-146a), lipoprotein-associated phospholipase A2 (Lp-PLA2) and renal function in patients with acute kidney injury (AKI) caused by sepsis. Methods A retrospective study was conducted on 88 patients with sepsis who were hospitalized in the Department of Infectious Diseases of our hospital from February 2020 to February 2022. According to whether AKI occurred within 24 hours of admission (including those who had AKI at the time of admission), 40 patients with AKI were set as observation group and 48 patients without AKI were set as observation group 2. Another 45 healthy physical examination subjects received by our physical examination center during the same period were selected as the control group. Serum miR-146a, Lp-PLA2 and renal function indexes of the three groups were detected and compared within 24h after admission/during physical examination. Patients were divided into shock group (7 cases), severe group (20 cases) and mild group (13 cases) according to the severity of septic AKI disease. Serum miR-146a, Lp-PLA2 and renal function indexes in different disease severity and AKI stage groups in patients with sepsis were compared. Pearson analyzed the correlation between miR-146a, Lp-PLA2 and renal function indexes, plotted receiver operating curve (ROC), and calculated the area under the curve (AUC). The predictive effects of miR-146a, Lp-PLA2 and renal function on AKI in sepsis were analyzed.Results Serum miR-146a, Lp-PLA2, cystatin C (Cys-C) and serum creatinine (Scr) in observation group 1 were higher than those in observation group 2 and control group within 24h after admission (P＜0.05). Serum miR-146a, Lp-PLA2, Cys-C and Scr in septic shock group were higher than those in severe and mild groups (P＜0.05). The serum miR-146a, Lp-PLA2, Cys-C and Scr in AKIIII group were higher than those in II and I groups (P＜0.05). Serum miR-146a and Lp-PLA2 were positively correlated with Cys-C and Scr within 24h after admission (P＜0.05) (r=0.421, 0.417, 0.398, 0.387). The AUC of serum miR-146a, Lp-PLA2, Cys-C and Scr combined detection to predict the occurrence of AKI in sepsis was 0.798 (95%CI:0.716-0.947), the sensitivity was 93.13%, and the specificity was 91.84%. The sensitivity and specificity of combined detection in predicting sepsis AKI were higher than those of single detection (P＜0.05).Conclusion Serum miR-146a and Lp-PLA2 in patients with sepsis AKI are highly expressed, which is correlated with renal function to a certain extent. Serum miR-146a and Lp-PLA2 combined with renal function detection can improve the sensitivity and specificity of predicting AKI, which has certain reference value in the diagnosis of AKI in patients with sepsis