The　piezoelectric　properties　of　bone　play　an　important　role　in　the　bone　remodeling　process　and　can　be　employed　in　clinical　bone　repair.　In　this　study,　the　piezo-voltage　of　bone　between　two　surfaces　of　a　bone　beam　under　bending　deformation　was　measured　using　an　ultra-high-input　impedance　bioamplifier.　The　influence　of　shear　stress　on　the　signs　of　piezo-voltages　in　bone　was　determined　by　comparing　and　contrasting　the　results　from　three-point　and　four-point　bending　experiments.　From　the　three-point　bending　experiment,　the　study　found　that　the　signs　of　piezo-voltages　depend　only　on　shear　stress　and　are　not　sensitive　to　the　normal　stress.