The objective of this study is to characterize the function of microRNA (miR)-124 in the process of coronary artery disease (CAD). Eighty patients, including 40 CAD patients and 40 non-CAD control patients were enrolled in this study. Atherosclerosis model was established in vivo in ApoE-/- mice and in vitro in RAW264.7 cells. Expression of miR-124 and p38 in patients, animal models and cell models were measured by qRT-PCR, western blot and immunohistochemistry assay. Overexpression or suppression of miR-124 was introduced in vitro and in vivo and the expression levels of p38, miR-124, pro- and anti-inflammatory cytokines, and pro- and anti-apoptotic factors were examined. Results showed that miR-124 was decreased, while p38 was increased in CAD patients and atherosclerosis models compared with control group. MiR-124 could target p38 by binding its 3’ untranslated region and negatively regulated the protein expression of p38. Overexpression of miR-124 increased the expression of anti-inflammatory cytokines, reduced the expression of pro- inflammatory cytokines, and inhibited macrophage apoptosis. MiR-124 overexpression may be a promising treatment for atherosclerosis and CAD via inhibiting p38.