Abstract: Objevtive To analyze the efficacy of losartan combined with spironolactone in the treatment of coronary artery microembolization and its effects on levels of serum matrix metalloproteinase-9(MMP-9), tissue inhibitor of metalloproteinase-1(TIMP-1), high sensitivity C reactive protein(hs-CRP). Methods Sixty-four patients with coronary artery microembolism admitted to our hospital were randomly divided into two groups. The control group(n=32)was treated with losartan, and the experimental group(n=32)was treated with lozafloxacin and spironolactone. The clinical efficacy, cardiac function indicators, serum MMP-9, TIMP-1, hs-CRP levels were compared. Results The total clinical effective rate in the experimental group was significantly higher than that in the control group(93.75% vs. 65.62%, P<0.05). After treatment, the experimental group had significantly lower results in left ventricular end-diastolic diameter(LVEDD), left ventricular end systolic diameter(LVESD), MMP-9, TIMP-1, hs-CRP levels than the control group, and left ventricular ejection fraction(LVEF)was significantly higher than that in the control group(P<0.05). Conclusion Losartan combined with spironolactone can effectively improve the clinical symptoms of patients with coronary artery microembolism, inhibit level of inflammatory factors such as hs-CRP, and improve the heart function.