Abstract: Objective To explore the correlation between the expression levels of microRNA-133, microRNA-208 and microRNA-499 in plasma of patients with coronary heart disease and the degree of coronary artery stenosis, so as to provide reference for further judging the degree of coronary artery stenosis in patients with coronary heart disease. Methods From January 2017 to December 2018, 150 patients with coronary heart disease who were hospitalized in the Department of Cardiology of Zhongshan Torch Development Zone Hospital of Guangdong Province were randomly selected as the observation group, while 150 patients with non-coronary heart disease were selected as the control group. Gensini scores and the expression levels of microRNA-133, microRNA-208 and microRNA-499 in plasma of the two groups were compared. The data were analyzed by SPSS 22.0. Results The plasma levels of microRNA-133, microRNA-208 and microRNA-499 in the observation group were higher than those in the control group(all P<0.05). According to Gensini score, 150 patients with coronary heart disease were further divided into three groups: 45 cases of mild stenosis group, 72 cases of moderate stenosis group, 33 cases of severe stenosis group. The expression levels of microRNA-133, microRNA-208 and microRNA-499 in plasma of three groups were significantly different(all P<0.001), mild stenosis group was lower than moderate stenosis group and severe stenosis group, moderate stenosis group was lower than severe stenosis group(all P<0.05), and the expression levels of microRNA-133, microRNA-208 and microRNA-499 in plasma of patients with coronary heart disease were positively correlated with Gensini score(all P<0.05). Conclusion The expression levels of microRNA-133, microRNA-208 and microRNA-499 in peripheral blood circulation have potential clinical value in monitoring the degree of coronary artery stenosis.