Study about measurement method of biomechanical property on dog's mandibular bone in vivo.When the main vertical occlusal force acting on mandibular molar,strain of mandibular bone in site was measured by the strain-electrometry.After the mechanical model was analyzed and calculated,elastic modulus of mandibular bone was 4.897×102 MPa. Biomechanical property of method and index on mandibular bone in vivo and quality of material about bone tissue were discussed.