This urinary metabonomic study aimed to identify the potential metabolic biomarkers in acute coronary syndrome (ACS) patients. Ultra-performance liquid chromatography/mass spectrometry (UPLC/MS) was used to analyze the urine samples from ACS patients and healthy controls. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were applied to characterizing the endogenous metabolites and potential biomarker, respectively. Among twenty biomarkers that functioned in nine metabolic pathways, nine biomarkers were found up-regulated significantly, including of isobutyryl‑l‑carnitine, 3‑methylglutarylcarnitine, cinnavalininate, l‑tryptophan, 3‑methyldioxyindole, palmitic acid, N4‑acetylaminobutanal, 3‑sulfino‑l‑alanine and S‑adenosyl‑l‑homocysteine. The other eleven biomarkers were showed down-regulated, including of l‑lactic acid, trigonelline, nicotinuric acid, l‑alanine, d‑alanyl‑d‑alanine, creatine, N4‑acetylaminobutanoate, glutathionyl spermidine, 5‑methoxytryptamine, kynurenic acid and xanthurenic acid. This study also implied that fatty acid metabolism, fatty acid β‑oxidation metabolism, amino acid metabolism and TCA cycle played important roles in ACS. Therefore, urinary metabolomics may improve the diagnosis efficacy of ACS and make it more accurate and comprehensive for ACS diagnosis.