OBJECTIVES:  To examine the use of secondary prevention medications including antiplatelets, beta-blockers, ACEIs/ARBs, and statins among patients with acute coronary syndromes (ACS) in Tianjin, China. METHODS:  Data were obtained from Tianjin Urban Employee Basic Medical Insurance database (2011-2014). Patients with primary discharge diagnosis of ACS during 2012.01.01-2013.12.31, and who were under the insurance cover for a minimum 12months before (baseline) and after (follow-up) index hospitalization were included. Patients were divided into two groups according to percutaneous coronary intervention (PCI) during index hospitalization. The use of secondary prevention medications was measured follow-up (0-3, 4-6, 7-9,10-12 months after discharge) for both total cohort and subgroups. Optimal medical therapy (OMT) was defined as receiving antiplatelet drug, statins, ACEIs/ARBs and β-blockers during the specific study period. RESULTS:  In total, 14,358 patients (64.7±10.7 years; 54.6% male) with ACS were identified. Of these 22.1% (N=3172) had PCI. They were significantly younger (62.3±10.0 vs. 65.4±10.8 years, P<0.001) and more were males (73.3% vs. 49.3%, P<0.001) compared with non-PCI group. Of total patients, 64.5% had ≥1 prescriptions of antiplatelets during 0-3 months, followed by statins (56.3%), ACEIs/ARBs (49.2%) and β-blockers (44.9%).The use of each medication class decreased gradually during follow-up. Only 22.9% of them were prescribed with OMT during 0-3 months, which decreased to 13.2% during 4-6 months, 10.6% during 7-9 months and 11.0% during 10-12 months. Compared with non-PCI group, PCI group had more patients with OMT during 0-3 months (46.3% vs. 16.3%, P<0.001), but it also decreased during 0-3, 4-6, 7-9,10-12 months (26.7%, 19.9% and 21.0%, respectively). CONCLUSIONS:  The use of secondary prevention medications and OMT were suboptimal and decreased over follow-up among Chinese ACS patients, including those with PCI procedure. Further strategies to promote the optimal medical care of ACS are needed.