Few of paperon alteration in thixotroplc properties of blood from patients with cerebral vascular diseases has been found yet. With Low Shear 30 rheometer, we modified the measuring protocol according to Huang's equation and determined the thixotroplc parameters of whole blood from 72 male patients with cerebral vascular diseases, thus we compared these parameters with those of blood from healthy subjects matched in sex and age. The results demonstrated that the yield stress, non-Newtonian contribution of viscosity',apparent viscosity (2.37 s-1) and the equilibrium value of structure parameters in the patients with cerebral arteriosclerosis (CA, n=14), transient cerebral ischemic attack (TIA, n=12) and cerebral thrombosis (n=46) were significantly higher than those of corresponding control groups. However, there were no significant changes In hematoerit, Newtonian contribution of viscosity and apparent kinetic rate constant of rouleaux breakdown. No significant differences of the thixotropic parameters existed among groups of CA, TIA and cerebral thrombosis. The results suggest that the patients with cerebral vascular diseases had evidently increased the amount and degree of RBC aggregation. Further more, before onset of cerebral thrombosis the patients with CA and TIA had already obvious change in thixotropy of blood. This probably implies that abnormality of thixotropy of blood is not a trigger factor for ischemic stroke, but a possible subsidiary or an associated risk factors.