This research was designed to illuminate the change in biomechanical parameters of soft tissue for bite marks on porker limb. The authors used a prefabricate nob to press perpendicularly on porket limb and so to establish bite mark under three forces: 100 N, 200 N and 300 N. After the procedure of biting, the stress-strain relationship and changes in extension of soft tissue were recorded. Meanwhile, the elasticity was measured with a press meter at nine time-points. When bite mark was formed, with the development of stress, the strain of soft tissue increased. But the speed of increment slowed down when stress exceeded some extent. After bite mark was formed, the extension and elasticity of soft tissue decreased with the increase of pressure.