Objective: To analyze the value of serum myeloperoxidase content detection for severity evaluation in patients with acute coronary syndrome. Methods: Acute coronary syndrome (ACS) group included 32 cases, stable angina pectoris (SAP) group included 46 cases, levels of myeloperoxidase (MPO), inflammatory factors and lipid metabolism indexes in serum were compared, coronary echocardiography blood flow parameters were detected, and the correlation between MPO and ACS severity-associated indexes was further analyzed. Results: MPO content in serum of ACS group was significantly higher than those of SAP group and control group; inflammatory factors hs-CRP, IL-6, MCP-1 and LP-PLA2 content in serum were higher than those of SAP group and control group while IL-13 and TGF毬 content were lower than those of SAP group and control group; lipid metabolism indexes TC, TG, LDL-C, ApoAI and ApoB content in serum were higher than those of SAP group and control group while HDL-C content was lower than that of SAP group and control group; ultrasonic coronary blood flow parameters SPV, DPV, A, CFVR and CTV栺 levels were lower than those of SAP group and control group. The serum MPO content in patients with ACS was directly correlated with the content of inflammatory factors and lipid metabolism indexes as well as the levels of coronary blood flow parameters. Conclusions: Serum MPO content in patients with ACS is directly correlated with the disease severity, and can be used as a reliable index for long-term guide of treatment and prediction of treatment outcome.