The simulation of organ-organ interaction is indispensable for practical and advanced medical VR simulator such as open surgery and indirect palpation. This paper gives a method to represent interaction between elastic objects i.e. organs in medical VR simulation. The proposed model defines displacements of colliding elements based on temporary surface forces caused by temporary displacements, so that the model produces accurate deformation and force feedback considering collisions of objects as well as prevents unrealistic overlap of objects. A prototype simulator of rectal palpation is constructed with the proposed model. The results of experiments confirmed the method expresses organ-organ interaction in real time and produces realistic and perceivable force feedback. Key words: Haptic display, Interaction, Elastic Objects, Medical simulation