The viscoelastic properties of thrombus play a significant role when the clot closes a leak in a vessel of the blood circulation. Therefore, it is important to evaluate the viscoelastic properties of blood clots in clinical applications. In this study, we perform the shear wave dispersion ultrasound vibrometry (SDUV) technique to characterize the thrombus at two different hematocrits. In thrombus experiments, two different hematocrits blood clots (hematocrit concentration 20% and 40%) were measured. The shear modulus is 422.7±66.2 for 20% hematocrit blood clot and 200.8±58.4 for 40% hematocrit blood clot. The viscosity is 0.37±0.02 for 20% hematocrit blood clot and 0.27±0.02 for 40% hematocrit blood clot.