Objective To investigate the correlation between plasma fibrinogen level and cerebral infarction （CI） as well as the difference of fibrinogen among subtypes of CI. Methods A case-controlled study was conducted with 131 cases of CI and 148 controls. Plasma fibrinogen levels were detected by the Clauss method. Results High fibrinogen level （3.09±0.94 g/L） was correlated with CI （OR=2.47

95%CI: 1.51-4.04

P<0.005） at the onset stage of the disease. Persistent high fibrinogen level （3.14±0.81 g/L） at 6-month after stroke onset was detected and correlated with CI（OR=4.34

95% CI:1.80-10.51

P=0.001）. Higher fibrinogen level was correlated with total anterior circulation infarction （TACI）

partial anterior circulation infarction （PACI）

and posterior circulation infarction （POCI） （OR=4.008

P<0.001）. Higher fibrinogen level was correlated with extracranial atherosclerosis （OR=3.220

P<0.05）

but not with intracranial atherosclerosis.Conclusion Fibrinogen level may be a risk factor of CI and probably correlates with subtypes of CI and distributions of atherosclerosis.