This paper proposes a finite element method (FEM)-based interaction modeling with multi-modal 3D meshes for neurosurgical simulation. The model solves a problem of overlapped region between meshes by defining new boundary and calculating mesh-mesh interaction. The proposed model considered energy preservation during collisions of objects. The method was implemented in the system with a haptic display. Simulation results showed real-time simulation of soft-body deformation with mesh-mesh interaction.