The　size　of　the　load　pad　had　a　significant　effect　on　the　output　of　the　column-type　force　transducer.　It　was　important　to　eliminate　the　influence　when　the　transducer　was　loaded　in　a　force　transducer　build-up　system　which　worked　as　the　primary　force　transfer　standard.　A　common　model　of　the　output　about　the　column-type　force　transducer　affected　by　the　shape　of　load　pad　was　analysed.　Seven　load　pads　with　various　dimensions　were　designed　and　fixed　on　a　300-kN　force　transducer　to　investigate　the　influence　of　the　dimension　on　the　indication　error　of　the　transducer.　The　results　showed　that　the　load　pad　of　the　sphere-plane　contact　design　would　cause　the　smallest　indication　error　but　the　largest　contact　stress.　It　was　better　to　use　the　load　pad　of　the　sphere-sphere　contact　design　with　the　spherical　radius　ratio　of　ball　to　cup　equalled　to　0.2.　The　spherical　radius　of　the　ball　should　be　small　under　the　permission　of　material　strength.　In　addition,　it　was　important　to　enhance　the　stiffness　of　the　build-up　system　to　eliminate　the　effect　of　the　load　pad　size　on　the　indication　error　of　the　transducer.