Abstract: Objective To explore the dynamic of high-sensitivity C-reactive protein (hs-CRP) and its correlation with insulin resistance (IR) during different stages of gestational diabetes mellitus (GDM). Methods Thirty-two subjects with GDM and thirty-one cases of normal glucose tolerance (NGT) pregnant women were enrolled in the study,fasting insulin (FINS) were determined by radioimmunoassay,the fasting blood glucose (FBG) was measured by using glucose oxidase,immunoturbidimetry performed to evaluate serum hs-CRP levels.Tests repeated for each group according different stages of prenatal 25-28 weeks,29-32 weeks,37-38 weeks and postpartum 6-8 weeks.IR was assessed by the homeostasis model assessment insulin resistance index (HOMA-IR),Results ①Serum hs-CRP levels in NGT and GDM had few change with gestational age,but both significantly decreased at postpartum.②Serum hs-CRP levels in GDM significantly increased than NGT in the same stage (t was 7.31,7.78,6.33,respectively,P<0.01).③HOMA-IR in GDM significantly increased than NGT in the same gestational stage (t was 31.18,31.10, 28.39,respectively,P<0.01).④Pearson correlation analysis showed that FBG,FINS and hs-CRP had significant association with HOMA-IR (regression coefficient of 0.478,0.902,0.293,respectively,P<0.01). Multiple regression analysis identified FINS,FBG and hs-CRP as the factors significantly affecting HOMA-IR (regression coefficient of 0.441,0.876,0.261,respectively,P<0.01).Conclusion Serum hs-CRP levels in GDM had few change with gestational age,but all significantly increased than NGT in the same stage,and which were the most significant factors affecting HOMA-IR.