Objective To investigate the clinical value of high-sensitivity troponin T (hs-cTnT) in the diagnosis of patients with acute myocardial infarction (AMI). Methods Serum hs-cTnT and routine cTnI concentrations from 240 AMI patients were measured by electrochemiluminescence immunoassay, and the receiver operating characteristic curve (ROC) was drawn. Based on the above curve, the cutoff value of hs-cTnT applying in clinical diagnosis was established and the accuracy of diagnosing AMI was compared between hs-cTnT and cTnI. Results The serum Hs-cTnT levels in AMI patients were more than 0.014 ng/mL (99th percentile value in healthy people), and the Hs-cTnT levels in ST elevation myocardial infarction (STEMI) patients were higher than that of non-ST-elevation myocardial infarction (NSTEMI) patients (χ2 = 68.573, P <0.05). The area under the ROC curve for hs-cTnT (AUC) was 0.905, which was significantly higher than the traditional cTnI of 0.793 (Z = 2.896, P <0.05). The combination of hs—cTnT and CK-MB resulted was increase with AUC from 0.905 to 0.954 (Z = 2.098, P <0.05). Taking 0.014 ng/mL as cut-off value, the diagnostic sensitivity of AMI could be 100%, but the specificity was only 45.5%. When taking 0.035 ng/mL as cut-off value which was the highest Youden index, the ability of diagnosing AMI comprehensively was the strongest, the diagnostic sensitivity and specificity could be 91.8% and 74.9%, respectively. Conclusion The diagnostic value of hs-cTnT for AMI was superior to conventional cTnI assay, but the improvement of the sensitivity also led to the hs-cTnT levels of non-AMI patients surpassing the cutoff value simultaneously，which should be paid attention for the differential diagnosis. While cutoff value of AMI corresponded to the highest Youden index in ROC curve, it was more applicable in clinical practice. There were still many issues about the detection and clinical applications of hs-cTnT, which need further clinical studies.