Both thighs of the dogs with or without ligated fern oral artery and vein were wounded. Thehemorheologic changes during 72 hours after trauma and the effect of the hemodynamics in atwinkle of the trauma on hemorheology were studied.The results suggested that the hemodynamicsin a twinkle of the trauma was one of the important reasons f'or blood viscosity and RBCaggregation increasing after trauma.