Aim Hereditary factor XI deficiency (FXID) is an autosomal inherited coagulation disorder characterized by mild bleeding disorder mainly associated with injury or surgery,which is related to a variety of mutations throughout the factor XI gene.This disorder is particularly common among Ashkenazi Jews with the main mutations of Glu117stop or Phe283Leu,and hereditary factor XI deficiency is also happened in other population,but is rare and with a wide genetic heterogeneity in the spectrum of disease-causative mutations.