Objective To compare the pancreatic β-cell functions of Han people between those with normal glucose tolerance (NGT),prediabetes (PD),and newly-diagnosed type 2 diabetes mellitus (NDDM), and to evaluate the value of the continuous glucose monitoring system (CGMS) in determining β-cell functions. Methods A total of 169 volunteers of Han people (20-75 years old, 72 male and 97 female) without diagnosed diabetes were given 75-g oral glucose tolerance test (OGTT) and insulin release tests. The body mass index (BMI) of the participants ranged from 18.5 to 28.0 kg/m2.They were categorized into NGT (n =87), PD (n =52) and NDDM (n =30) groups according to the World Health Organization (WHO) 1999 criteria.Blood samples were taken to test triglyceride