Abstract: Objective: To study the clinical value of the changes of D-dimer (D-D),prothrombin time (PT),activated partial thrombopastin time (APTT),thrombin time (TT) and fibrinogen (FIB) in women during normal pregnancy and 3 days after delivery.Methods: The D-D,PT,APTT,FIB and TT of 80 healthy women (control group),240 normal pregnant women who were divided into 3 groups in accordance to the gestational weeks,and 80 three-day-postpartum women were determined using the hemagglutinin analyzer.Results: The PT in three-day-postpartum women was higher than the other groups (P<0.05-P<0.01),but PT in the prepregnancy,mid-pregnancy and late-pregnancy group were higher than the control group (P<0.01);the FIB,APTT and D-D were statistically different in the mid-pregnancy group and the late-pregnancy group compared with those in other groups (P<0.05-P<0.01);the TT in the late-pregnancy group was significantly lower than the control group and the three-day-postpartum women (P<0.05).Conclusions: Normal pregnant women are in a hypercoagulable state which is resumed about three days after delivery.Routine coagulation tests can be of great significance in preventing thrombosis in pregnant women.