The expression of resistin protein in normal human abdominal, thigh, pregnant women abdominal, non-pregnant women abdominal subcutaneous adipose tissue and placenta and the relationship between obesity, type 2 diabetes mellitus (T2DM), pregnant physiological insulin resistance (IR) and gestational diabetes mellitus (GDM) was investigated. The expression of resistin protein in normal human abdominal, thigh, pregnant women abdominal, non-pregnant women abdominal subcutaneous adipose tissue and placenta was detected by using Western blotting method. Fasting serum glucose concentration was measured by glucose oxidase assay. Serum cholesterol (CHOL), serum triglycerides (TG), serum HDL cholesterol (HDL-C) and serum LDL cholesterol (LDL-C) were determined by full automatic biochemical instrument. Fasting insulin was measured by enzyme immunoassay to calculate insulin resistance index (IRI). Height, weight, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured to calculate body mass index (BMI) and body fat percentage (BF %). Resistin protein expression in pregnant women placental tissue (67 905±8441) (arbitrary A values) was much higher than that in subcutaneous adipose tissue in pregnant women abdomen (40 718±3818, P<0.01), non-pregnant women abdomen (38 288±2084, P<0.01), normal human abdomen (39 421±6087, P<0.01) and thigh (14 942±6706, P<0.001) respectively. The resistin expression in abdominal subcutaneous adipose tissue showed no significant difference among pregnant, non-pregnant women and normal human, but much higher than that in thigh subcutaneous adipose tissue (P<0.001). Pearson analysis revealed that resistin protein was correlated with BMI (r=0.42), fasting insulin concentration (r=0.38), IRI (r=0.34), BF % (r=0.43) and fasting glucose (r=0.39), but not with blood pressure, CHOL, TG, HDL-C and LDL-C. It was suggested that resistin protein expression in human abdominal subcutaneous adipose tissue was much higher than that in human thigh subcutaneous adipose tissue. Resistin was closely related with central obesity, leading to IR, subsequently obesity and T2DM. Resistin protein expression in placental tissue was much higher than that in subcutaneous adipose tissue in normal human abdomen, pregnant abdomen, non-pregnant women abdomen and thigh. It was indicated that resistin protein could be secreted from human placental tissue. Resistin might be one of the factors that lead to pregnant physiological IR and GDM.