Background: Several platelet function tests are currently used to measure responsiveness to antiplatelet therapy.This study was to compare two tests, light transmittance aggregometry (LTA) and modified thrombelastography (mTEG), for predicting clinical outcomes in Chinese patients after percutaneous coronary intervention (PCI).Methods: Prospective, observational, single-center study of 789 Chinese patients undergoing PCI was enrolled.This study was investigated the correlations between the two tests and performed receiver operating characteristic curve (ROC) analysis for major adverse cardiovascular events (MACEs) at l-year follow-up.Results: MACEs occurred in 32 patients (4.1%).Correlations were well between the two tests in the adenosine diphosphate induced platelet reactivity (Spearman r =0.733, P < 0.001).ROC-curve analysis demonstrated that LTA (area under the curve [AUC]: 0.677;95% confidence interval [CI]: 0.643-0.710;P =0.0009), and mTEG (AUC: 0.684;95% CI: 0.650-0.716;P =0.0001) had moderate ability to discriminate between patients with and without MACE.MACE occurred more frequently in patients with high on-treatment platelet reactivity (HPR) when assessed by LTA (7.4% vs.2.7%;P < 0.001), and by TEG (6.7% vs.2.6%;P < 0.001).Kaplan-Meier analysis demonstrated that HPR based on the LTA and mTEG was associated with almost 3-fold increased risk of MACE at 1-year follow-up.Conclusions: The correlation between LTA and mTEG is relatively high in Chinese patients.HPR measured by LTA and mTEG were significantly associated with MACE in Chinese patients undergoing PCI.