Abstract: Objective To investigate the expression and clinical significance of serum adipocytokines C1q/tumor necrosis factor-related protein (CTRP) 6 and CTRP9 in patients with gestational diabetes mellitus (GDM).Methods A total of 35 pregnant women who were admitted to the Affiliated Huai'an First People's Hospital of Nanjing Medical University from October 2019 to October 2020 and diagnosed with GDM were selected and set a GDM group. Meanwhile, another 37 normal pregnant women who underwent examination at the same period were included in a control group. Both groups were compared for general information, blood lipid, hepatic and renal function, fasting plasma glucose (FPG), fasting insulin (FINS) and homeostasis model insulin resistance index (HOMA-IR). The levels of serum CTRP6 and CTRP9 were measured by enzyme-linked immunosorbent assay (ELISA). The amounts of IL-6 and TNF-α were examined by Luminex-xMAP technology. The diagnostic value of CTRP6 and CTRP9 was analyzed by the receiver operating characteristic (ROC) curve.Results The levels of serum CTRP6, CTRP9, IL-6 and TNF-α were obviously higher in the GDM group, compared with the control group (P<0.001). Pearson correlation analysis indicated that serum CTRP6 was positively correlated with FPG (r=0.280, P=0.017) and HOMA-IR (r=0.250, P=0.035). Furthermore, CTRP9 was positively correlated with FPG (r=0.559, P<0.001), FINS (r=0.253, P=0.032), HOMA-IR (r=0.382, P=0.001), IL-6 (r=0.283, P=0.016), and TNF-α (r=0.266, P=0.024). According to ROC curve analysis, the area under the curve (AUC) of serum CTRP6 and CTRP9 alone and their combination in predicting GDM was 0.914, 0.914 and 0.974, respectively.Conclusions The levels of serum CTRP6 and CTRP9 in GDM patients are elevated, which may be related to insulin resistance. CTRP6 and CTRP9 have a certain value for the diagnosis of GDM patients, while the combined detection of CTRP6 and CTRP9 can improve the predictive value of GDM to a certain extent.