To study the effect of hypertonic saline solution on the rheology and putative mechanism, we investigated the changes of plasma viscosity, blood viscosity and reduced viscosity in dogs treated with hypertonic saline solution after burn-blast combined injury and observed the effect of hypertonic saline solution therapy on the viscoelastic property of erythrocyte membranes measured by micropippette aspiration technique in rats with burn. The results showed that the blood viscosity and reduced viscosity increased significantly in dogs after injury, and plasma viscosity also increased significantly at 24 h after injury. Elastic moduli and viscous coefficients of erythrocyte membranes increased obviously in rats after burn. The hypertonic saline solution therapy could significantly improve blood viscosity and reduced viscosity, but it did not significantly improve elastic moduli and viscous coefficients of erythrocyte membranes. These suggested that the hardness of erythrocyte membranes increased, the deform property of erythrocyte membranes decreased, and the blood rheology became worse after burn blast combined injury. Hypertonic saline solution therapy could significantly improve the blood rheology. The effect did not bear a significant relationship with the change of single biomechanics property of erythrocyte membranes. It might be related with other factors.