Objective Calibrated Automated Thrombogram(CAT) is a test to monitor the generation of thrombin. It can be described by four parameters:lag time, peak thrombin, endogenous thrombin potential (ETP) and time to peak (ttPeak). This study aims to determine the normal ranges of CAT parameters in Chinese, and evaluate whether thrombin generation is correlated with the concentration of heparin/low molecular weight heparin. Methods Plasma from 120 healthy subjects were collected to determine the normal rangea of CAT parameters in Chinese. Normal plasma pool (NPP, n=25) spiked with different concentrations of heparin or enoxaparin were used to detecte CAT parameters. The overall and age specific normal ranges of CAT parameters were calculated using descriptive statistics method with mean±2SD. The correlation between CAT parameters and age or concentrations of heparin, enoxaparin were analyzed with linear regression model. Results The normal ranges for lag time, peak thrombin, ETP, ttPeak in the subjects were 3.648±2.465 min, 367.39±151.93 nmol/L, 2277±1030 nmol/L·min and 6.372±4.280 min respectively. Age was linearly correlated with lag time (r=-0.6583, P