Abstract: Objective　To investigate the progression of hyperinsulinism(HINS) in different development phases of type 2 diabetes mellitus （T2DM）.  Methods　A total of 38 pre-T2DM patients，52 newly diagnosed T2DM patients and 92 patients who had T2DM history were enrolled. According to the course of T2DM，the patients with T2DM history were classified into 3 groups：0.5-3 years，4-7 years and 8-11 years， and 20 healthy subjects were as controls. The glycosylated hemoglobin (HbA1c)，blood glucose，insulin and C peptide were determined．Homeostasis model of insulin resistance index（HOMA2-IR） and secretion function index (HOMA2-%β) were calculated by HOMA2 calculator (V2.2) downloaded from www.ocdem. ox.ac.uk.  Results　All T2DM groups′ secretion peaks appeared in 2 h of oral glucose tolerance test(OGTT)， and all presented secretion delay. The 2 h insulin levels of the pre-T2DM and newly diagnosed T2DM groups were higher than HINS diagnosis standard，and the HINS patients accounted for 50.00% and 48.10%， respectively. With the increasing of T2DM course，the proportions of HINS patients in the T2DM history group were 28.57%，13.89% and 10.00%， respectively.  Conclusions　There is a proportion of pre-T2DM patients with HINS，and with the increasing of T2DM course，the proportion of HINS patients reduces，but HINS still exists in patients with long history of T2DM.

Key words: Hyperinsulinism, Pancreatic function, Diabetes mellitus, type 2