OBJECTIVE: High-sensitivity C-reactive protein (hs-CRP) may predict the development of type 2 diabetes mellitus (T2DM), metabolic syndrome (MS) and cardiovascular diseases (CVD) in adult, but few reports on relevant studies in children are available. The present study aimed to understand possible correlation between serum hs-CRP levels and some factors of obese children and adolescents with or without impaired glycometabolism. METHODS: Seventy obese children and adolescents (age 8 - 17 years) and 30 non-obese healthy controls (group 1, 20 boys and 10 girls, mean age 12.6 years) were enrolled into this study. The obese individuals were subdivided into two groups according to the results of oral glucose tolerance test: the obese subjects without IGR (group 2, 54 cases, 43 boys and 11 girls, mean age 11.3 years) and the obese subjects with impaired glycometabolism (group 3, 16 cases, 8 boys and 8 girls, mean age 12.8 years). The levels of serum parameters including hs-CRP, glucose, lipid, insulin, C-peptide and whole blood HbA1c were determined. SPSS 10.0 was used for statistical analysis. RESULTS: (1) There was significant increase of serum hs-CRP level in obese children and adolescents, the median was 2.44 (0.01 - 14.6) mg/L; the level of control group was 0.1 (0.01 - 2.1) mg/L. (2) Some of the following parameters, such as fasting plasma glucose (FPG), triglyceride (TG), fasting insulin (FINS), C-peptide (Cp) and insulin resistance index (IRI), were found increased in group 2 and 3 as compared to group 1. When FPG and TG were still in normal range in group 2, the levels of hs-CRP and IRI were significantly higher than those in group 1, the level of hs-CRP was 2.4 (0.01 - 9.0) mg/L. While FPG and TG were abnormal in group 3, the level of hs-CRP was 2.6 (0.1 - 14.6) mg/L, but the difference had no statistical significance. (3) Pearson correlation analysis showed that there was a moderate correlation between serum hs-CRP and BMI (r = 0.414, P = 0.000). There was a low correlation between hs-CRP and waist circumference, hip circumference and waist to hip ratio (WHR). The correlation of serum hs-CRP with blood pressure, TG, cholesterol, high density lipoprotein-cholesterol (HDL-C), HbA1c, FPG, FINS and Cp had no significant deviation. (4) Multiple linear regression analysis showed that body mass index (BMI) was the only indicator which had correlation with hs-CRP. CONCLUSION: (1) There may be a chronic low-grade inflammation and insulin resistance in obese children. (2) The level of hs-CRP might be independently correlated with BMI in children. (3) Hs-CRP and IRI elevated before FPG and TG did, which may suggest that the low-grade inflammation and insulin resistance may be a pathogenic base of DM rather than the outcome of it. (4) The elevation of hs-CRP may help predict impaired glucose and lipid metabolism.