Abstract: Objective To study the coagulation and fibrinolytic markers in the first trimester of pregnant women with polycystic ovary syndrome (PCOS) and normal pregnant women. Methods One hundred pregnant women who visited the Outpatient Department of Obstetrics and Gynecology, Navy General Hospital of Chinese PLA, from April 2011 to May 2012, were divided into PCOS pregnant group (n=50) and normal pregnant group (n=50).Their coagulation and fibrinolytic markers were detected. Results The activity of coagulation factor Ⅷ (F Ⅷ) and coagulation factor X (F X) and the levels of von Willebrand factor (vWF), plasminogen activator inhibitor 1(PAI-1)and tissue plasminogen activator t-PA were significantly higher in PCOS pregnant group than in normal pregnant group (P< 0.05).However, no significant difference was observed in D-dimer level between the two groups. Conclusion The levels of F Ⅷ, vWF and F X can accurately predict the hypercoagulable state in the first trimester of pregnant women with PCOS.