Abstract: Objective To investigate the change of the levels of fasting plasma endotoxin (ET) and assess its correlated factors in individuals with different glucose tolerances and body mass indices. Methods The levels of fasting plasma ET were assayed by the endpoint chromogenic limulus amebocyte lysate method in subjects with type 2 diabetes (T2DM), impaired glucose regulation (IGR) and normal glucose tolerance (NGT). The height, body mass, waist, hips, systolic blood pressure and diastolic blood pressure were measured with the conventional methods; body mass index (BMI) and waist hip ratio (WHR) were calculated. All groups were divided into obesity (BMI ≥ 25 kg/m²) and non-obesity (BMI<25 kg/m²) subgroups. The levels of fasting blood glucose (FBG), 2 hours plasma glucose (2 hPG), fasting insulin (FINS), postprandial insulin (PINS), hemoglobin A1c (HbA1c), blood lipids, free fatty acids (FFA), serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were also analyzed, and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. The relationship of the levels of plasma ET with age, BMI, WHR, blood pressure, FBG, 2 hPG, FINS, PINS, HOMA-IR, HbA1c, blood lipids, FFA, AST and ALT were also analyzed. Results ①The levels of plasma ET in T2DM group (n=37) was significantly higher than that in NGT group (n=37)7.1 (3.7-11.8) EU/mL vs. 4.5 (2.2-6.3) EU/mL, P<0.05. The levels of plasma ET in IGR group (n=23)5.0 (2.4-10.3) EU/mL was lower than that in T2DM group and higher than NGT group but the differences were not significant (P>0.05). ② The levels of plasma ET in the obesity T2DM subgroup was higher than that in the non-obesity T2DM subgroup but the differences were not significant7.3 (3.8-13.3) EU/mL vs. 7.0 (3.6-10.4) EU/mL, P>0.05.There was a remarkable difference in the levels of plasma ET between obesity and non-obesity subgroup of IGR6.8(2.9-13.2) EU/mL vs. 2.7 (1.6-5.5) EU/mL, P<0.05, similarly between obesity and non-obesity subgroup of NGT6.2 (3.4-12.7) EU/mL vs. 2.8 (1.8-4.9) EU/mL, P<0.05.③ Multiple linear regression analysis demonstrated that ET wasn't the important factor influencing FBG and 2 hPG.But BMI and FBG were the important factors influencing ET. 2 hPG and WHR weren't the important factors influencing ET. Conclusion With the increase in glucose metabolic abnormalities and BMI, the levels of plasma ET are gradually increased. ET isn't the important factor influencing FBG and 2 hPG. BMI and FBG are the important factors in influencing ET.