Objective To investigate effects of Danhong on the serum levels of CD137, high-sensitivity C-reactive protein (hs-CRP) and homocysteine (Hcy) in patients with non-ST elevation acute myocardial infarction complicating metabolic syndrome. Methods A total of 126 patients with non-ST elevation acute myocardial infarction complicating metabolic syndrome were enrolled and randomly divided into a conventional treatment group and a Danhong treatment group using a random-digit table, with 63 patients in each group. All patients underwent angiography or percutaneous coronary intervention. The patients in the Danhong treatment group treated with intravenous Danhong 20 ml on the basis of conventional treatment for 1 week. The serum levels of CD137, hs-CRP and Hcy were measured at hospital admission and 10 days after treatment. The severity of coronary artery disease was assessed by the Gensini-score. Results The levels of CD137, hs-CRP and Hcy in both groups after treatment were significantly lower than before treatment (conventional treatment group: t 12.393, 17.408 and 9.458; Danhong treatment group: t 16.110, 17.573 and 13.481; all P<0.01), and the Danhong treatment group were significantly decreased than the conventional treatment group (t 2.815, 3.224 and 3.157, all P<0.01). The serum levels of CD137 and hs-CRP before treatment were significantly correlated with Gensini scores in 126 patients (r 0.720 and 0.562,all P<0.01). Conclusions The serum levels of CD137 and hs-CRP are significantly correlated with the severity of coronary artery disease, intravenous Danhong may has protective effect for coronary artery disease via decreasing CD137 and hs-CRP.