Objective:To investigate the relationship between the expression of serum microRNA-16(miR-16)and depression in patients with acute cerebral infarction(ACI).Methods:A total of 189 ACI patients treated in Neurol-ogy Department of Zigong First People's Hospital between December 2019 and September 2021 were selected as the disease group,and another 175 healthy volunteers who simultaneously underwent physical examination in our hospi-tal were selected as healthy group.The expression of serum miR-16 was detected by quantitative real time polymer-ase linked reaction(qRT-PCR).ACI patients was divided into depression group(n=56)and no depression group(n=133)according to presence of depression during 6-month follow-up after treatment.Serum miR-16 expres-sion and general data were compared between two groups.Multivariate Logistic regression was used to analyze influ-encing factors of depression in ACI patients.Results:The expression of serum miR-16[(13.24±2.41)vs.(5.76±1.02)]in the disease group was significantly higher than that of healthy group(P<0.001).After 6-month fol-low-up,the incidence of depression was 29.63%among the 189 ACI patients.Compared with no depression group,patients in depression group had significant higher serum miR-16 expression[(12.75±2.23)vs.(14.42±2.68)],score of National Institute of Health Stroke Scale(NIHSS)at admission[(15.12±2.88)points vs.(18.23±3.42)points],proportions of introversion(38.35%vs.67.86%)and aphasia(43.61%vs.62.50%),and signif-icant lower Barthel index score[(56.24±9.89)points vs.(48.41±9.45)points](P<0.05 or<0.01).Multivari-ate Logistic regression analysis suggested that serum miR-16 expression(OR=3.071,95%CI 1.653~5.562,P<0.001),introversion(OR=4.623,95%CI 2.321~6.589,P=0.009),aphasia(OR=3.854,95%CI 1.785~6.112,P<0.001)and NIHSS score at admission(OR=4.354,95%CI 2.121~6.563,P<0.001)were independent risk factors for depression in ACI patients,while Barthel index score was its independent protective factor(OR=0.626,95%CI 0.335~0.914,P=0.017).Conclusion:The expression of serum miR-16 in ACI patients is signifi-cantly higher than that of healthy people.Serum miR-16 expression,introversion,aphasia,NIHSS score at admis-sion and Barthel index score are all independent influencing factors for depression in ACI patients.