Objective：To investigate the thrombin function and platelet function of woman with pregnancy associated thrombocytopenia （PAT） and the correlation between platelet count and postpartum hemorrhage and perinatal outcome. Methods：Clinical data of 41 cases of PAT women who delivered in our hospital from September 2012 to December 2012 were analyzed prospectively. Thrombin function，platelet function，volume of bleeding in delivery，occurrence rate of postpartum hemorrhage and birth weight of the newborns were included. All women with PAT were divided into 3 groups as below：group 1 with platelet count of （80-99）×109/L，group 2 with platelet count of （50-79）×109/L and group 3 with platelet count below 50×109/L. Results：There was no significant difference in pro－thrombin time，activated partial thromboplastin time and abnormity rates of platelet aggregation between normal control group and PAT women groups（P ＞0.05）. Volume of bleeding was higher in group 3 than in group 2 and group 1，with significant differences（P＜0.05）. Coefficient of correlation（r） between the weight of the newborns and platelet count was 0.18（P ＞0.05）. Conclusions：Thrombin func－tion and platelet function of PAT women are not affected by platelet count. Risk of postpartum hemorrhage is not higher in mild and middle grade PAT women than in normal pregnant women，but severe PAT women have higher risk of postpartum hemorrhage.De－creasing degree of platelet in PAT women will not affect perinatal outcome.