Aim To observe the level of apolipoprotein CⅢ(ApoCⅢ) in the serum between the patients with acute myocardial infarction and non-coronary heart disease whether they were significantly different, and to explore its clinical significance. Methods A total of 110 patients were enrolled. They were divided into acute myocardial infarction group and non-coronary heart disease group, including 84 people in acute myocardial infarction group, and 26 people in non-coronary heart disease group. The clinical data of patients during hospitalization were collected, including general information such as age, sex, hypertension, diabetes mellitus, dyslipidemia, smoking history, and blood biochemical index data, including serum troponin I(cTnI), triglyceride(TG), total cholesterol(TC), low density lipoprotein cholesterol (LDLC), high density lipoprotein cholesterol (HDLC), uric acid(UA), homocysteine, serum brain natriuretic peptide (BNP), ejection fraction (EF), and serum inflammation index data, including serum cystatin C (CysC) and high-sensitivity C-reactive protein (hs-CRP). The levels of serum apolipoprotein CⅢ in each patient were measured. Results Compared with non-coronary heart disease group (P<0.05), there were more males in the myocardial infarction group, and smoking rate was higher than that of non-coronary heart disease group (P<0.05). Serum cTnI and serum BNP in patients with myocardial infarction were higher than those in non-coronary heart disease group (P<0.05), while HDLC and EF were lower than those of non-coronary heart disease group (P<0.05). The levels of serum CysC, hs-CRP and apolipoprotein CⅢ in the myocardial infarction group were significantly higher than those in the non-coronary heart disease group (P<0.01). Multivariate linear regression analysis showed that there was no significant correlation between apolipoprotein CIII and sex, smoking history, HDLC, cTnI, BNP, EF, CysC, hs-CRP which were significantly different between the two groups. Conclusion The levels of serum apolipoprotein CⅢ in patients with acute myocardial infarction were significantly higher than those in patients without coronary heart disease. Considering that apolipoprotein CⅢ promotes the formation of atherosclerosis by affecting blood lipid metabolism and the process involves a variety of inflammatory mediators, apolipoprotein CⅢ may be a predictor of inflammatory response to acute myocardial infarction.