In recent medical field, surgical simulators with the technique of virtual reality are expected to provide a new means to support the surgical front. We have developed a simulation for brain surgery using a dynamic deformation model. Most of physics models, including the dynamic deformation model, are required to identify the physical properties of target tissues. In this research, we identified physical properties of swine liver. Young's Modulus, Poisson's Ratio and damping coefficient is necessary for the simulation. There are previous researches about identification of Young's Modulus, but that about identification of Poisson's Ratio and damping coefficient are few. Therefore, in this research, we conduct tension experiments to measure Young's Modulus and Poisson's Ratio, and vibration experiments to measure damping coefficient.