Abstract: Objective: To explore the clinical significance the activation state of blood platelet in patients with hypertension disorder in pregnancy.Methods: The expression of activated fibrinogen receptor on the surface of blood platelet in patients with hypertension disorder in pregnancy was determined in whole blood by flow cytometry(FCM),and four parameters of blood coagulatlon were tested by chromogenic assays.Results: The intensity and the ratio of activated blood platelet in pregnant women with hypertension disorder were significantly higher than those in normal gravida and non-pregnant women (P<0.01).There was significant difference in prothrombin time(PT) and activated partial thromboplatin time(APTT) between pregnant women with hypertension disorder,normal gravida and non-pregnant women,but no significant difference of coagulation time and fibrinogen between them was found.Conclusions: Comparing with assay of four parameters of blood coagulation,detection of activated fibrinogen receptor on surface of blood platelet in whole blood by FCM can reflect the activation state of blood platelet and evaluate the state of the disease in pregnant women with hypertension disorders.It can serve as an early indicator to predict and diagnose preeclampsi of the disease and tendency of disseminated intravascular coagulation.