Abstract： Objective To analyze the islet β cell function and the insulin resistance of different components of impaired glucose regulation(IGR).Methods A total of 463 adults diagnosed as IGR and 200 adults diagnosed as NGT by 75g OGTT,were included for the analysis of the islet beta cell function and insulin resistance.Results In the IFG group,HOMA-IR was significantly higher than in NGT and IGT group(P<0.05),ISI-Stumvoll was lower than in NGT group,but higher than in IGT group(P<0.05);HBCI/IR were lower than in the two groups(P<0.05).HOMA-IR and HBCI/IR of IGT group were between the NGT group and the IFG group.ISI-Stumvoll,the first and second phase insulin secretion index were significantly lower in IGT group than in NGT group and IFG group(P<0.05).In the IFG plus IGT group,HOMA-IR was the highest among all the groups;ISI-Stumvoll was lower than the NGT group and the IFG group;HBCI/IR were lower than the NGT group and the IGT group;the first and second phase insulin secretion index were the lowest among all the groups.In the non-diabetic population,along with the increasing of fasting plasma glucose(FPG) or 2h plasma glucose(2hPG),HOMA-IR was increased gradually,ISI-Stumvoll and the first and second phase insulin secretion indexes were decreased gradually(P<0.05).Conclusions IFG is originatd from severe hepatic insulin resistance and basal islet β cell dysfunction.IGT is originated from marked peripheral insulin resistance,and post-glucose-loading β cell dysfunction with near-normal basal insulin secretion.In the non-diabetic groups,FPG and 2hPG are positively correlated with insulin resistance,and negatively correlated with islet β cell function