In this paper, we performed the dynamic measurement and modeling of soft tissue with removing samples from the main body to characterize the soft tissue properties for medical simulations. The measurement method made various patterns of normal surface indentations of a soft tissue. Next, the reaction forces through the indenter were measured using a force transducer. From the force-displacement profile, the nonlinear properties were observed in a relatively small deformation range and the frequency responses of the tissue were obtained using a series of sinusoidal indentations below 3 Hz. We developed a viscoelastic model of the tissues from the recorded force-displacement profiles, from which we can develop a model to predict the behavior of the tissues. The developed model, combined with the anatomical model, could provide a visible deformation and haptic feedback for virtual reality based medical simulations.