Abstract: The influence of shear modulus and viscosity to the ultrasound field of microbubble enhanced high intensity focused ultrasound was discussed.The numerical simulation model was established based on the gas-liquid mixing acoustic propagation equation, Yang-Church bubble motion equation, the finite difference time domain (FDTD) method and Runge-Kutta (RK) method. The HIFU pressure field with different shear modulus and viscosity of tissue mimicking phantom was evaluated.The results showed that, as the shear modulus increasing, the pressure at focus decreases and the focus move closer to the transducer side; as the viscosity increasing, the pressure at focus increases and the focus position without clear shift.