Objective To compare the differences of clotting laboratory indices and thromboelastogram (TEG) parameters between pregnant women with gestational diabetes mellitus (GDM ) and healthy pregnant women .Methods The detection results of clotting laboratory indices and TEG in 46 pregnant women with GDM and 49 healthy pregnant women in our hospital from June 2013 to July 2014 were retrospectively analyzed and compared .Results In the comparison of the GDM group and the control group ,the traditional clotting laboratory indices ,INR and PT had statistically significant differences(P<0 .05) .However ,other tra‐ditional clotting laboratory indices ,like APTT ,FIB ,PLT showed no statistically significant differences (P>0 .05) .The common TEG indices of R value ,K value ,Angle ,MA value and CI value were statistically different between the GDM group and control group(P<0 .05) .Conclusion TEG is more sensitive than traditional clotting detection in monitoring the prethrombotic state of pregnant women with GDM and has certain significance for guiding early clinical intervention ,alleviating or delaying complications and improving the maternal and infantile outcome .