It is important about the correlative study between hemorheology and cerebral heraodynamics forthe diagnosis and teatment of cerebral vascular diseases. The results of the correlative study on thepatients with hypertension.cerebral infarction and non-cardio-vascular disease in this study haveshowed that, the parameters of cerebral hemodynamics are obviousely affected by the hematocrit,these parameters are also correlative with other hemorheologic parameter-high shear stressviscosity of whole blood, plasma viscosity, low shear stress viscosity of whole blood, erythrocyteaggregation index, erythrocyte sedimentation.The effect degree of hematocrit on the cerebralhemodynamics parameters is diastolic pressure, dilation index of blood vessels, cerebral vascularresistance,critical pressure, transmission velocity of waves in cerbral artery from high to low. Thecomparison of parameters between cerebral hemodynamics and emorheology show that the former iscloser than the later on the correlative with the pathologic changes of hypertension and cerebral infarction.