Objective · To explore the changes of blood coagulation parameters before delivery and their correlation with blood glucose. Methods · The basic clinical data and blood samples were collected from 132 pregnant women with GDM and 160 healthy pregnant women who were near labor in the third trimester. The levels of blood glucose and coagulation-related indicators, including the values of oral glucose tolerance test (OGTT) at 0, 1 and 2 h, activated partial thromboplastin time (APTT), thrombin time (TT), pro-thrombin time (PT), D-dimer, fibrinogen (FIB) and international normalized ratio (INR), were detected, and the statistical analysis was carried out. Results · The levels of FIB and INR in the GDM group were significantly higher than those in the control group (P=0.003, P=0.005). There were no significant differences between the two groups on the levels of APTT, TT, PT, and D-dimer (all P>0.05). The level of FIB was significantly positively correlated with the values of OGTT at 1 h (P=0.000) and 2 h (P=0.000), and the level of FIB had no correlation with the value of OGTT at 0 h (P=0.505). There was no correlation between the level of INR and all the OGTT values (all P>0.05). Conclusion · Plasma FIB levels of GDM women were significantly increased before delivery, and FIB was significantly positively correlated with the values of OGTT at 1 h and 2 h.