Abstract: Objective To investigate the relationship between serum level of highly sensitive C-reactive protein (hs-CRP) and insulin sensitivity in type 2 diabetic patients. Methods Serum hs-CRP level was determined by highly sensitive enzyme-linked immunosorbent assay (ELISA) in 65 patients with type 2 diabetes and 25 normal controls. Plasma glucose, serum insulin, glycosylated hemoglobin (HbA1c), urinary albumin excretion rate (UAER), plasma lipids and lipoprotein were also measured. Moreover, homeostasis model analysis (HOMA) of insulin resistance index (HOMA-IR) and islet secretion index (HOMA-IS) were calculated to estimate the insulin sensitivity and islet function. Results In the patients with type 2 diabetes, serum hs-CRP was increased, HOMA-IR index and HOMA-IS index were decreased as compared with the normal control subjects (P<0.01). Moreover, serum hs-CRP was significantly higher in poorly controlled diabetic patients (n=23) with HbA1c≥7% than that in well controlled diabetic patients (n=42) with HbA1c<7%. Liner regression analysis in diabetic patients showed that serum hs-CRP was negatively correlated with HOMA-IS index but positively correlated with fasting plasma glucose, body mass index, HbA1c and diastolic blood pressure, respectively. Conclusion Serum HS-CRP level is higher in the patients with type 2 diabetes than in normal subjects, and plays an role in the development and progression of type 2 diabetes mellitus.