Abstract: Objective:To discuss the influencing factors of increased plasma D-dimer level in patients with bone fracture. Method:Plasma D -dimmer levels of 235 fracture patients were detected using latex enhanced immune turbidimetric method on Sysmex CA-7 000 type automatic blood coagulation analyzer, and the relationship between gender, age and disease severity and the D-dimer were analyzed. Result:Plasma D-dimer levels in fracture patients group were significantly higher than that in normal control group (P<0.05). Plasma D-dimer in age less than 25 years old fracture patients had no obviously difference compared with normal control group (P>0.05). Along with the increase of age, D-dimer significantly increased, especially in patients older than 50 years (P<0.05).According to the fracture site, injury was classified into 3 degrees, namely slight, medium and heavy. In simple closed slight fracture patients, the D-dimer change had no obvious difference compared with healthy controls. With the increase of fracture serious degree, plasma D-dimer was higher than control group (P<0.05), especially[HK]