To　improve　static　and　dynamic　performances　of　rotary　table,　the　effects　of　configurations,　assembling　technology　and　external　load　on　the　static　stiffness　of　a　three-row　cylindrical　roller　bearing　for　rotary　table　are　investigated.　A　theoretical　model　of　static　stiffness　of　three-row　cylindrical　bearing　for　rotary　table　is　proposed　considering　the　clearance,　bolt　preloads,　and　reactions　of　axial　and　radial　rollers　with　external　load.　The　contacts　between　the　axial　rollers　and　the　outer　ring　are　treated　as　ideal　plane　contact.　And　the　actual　contact　forces　and　their　distribution　along　the　axial　of　radial　rollers　are　obtained　by　Boussinesq＇s　relationship　between　force　and　deformation,　the　static　stiffness　in　five　directions　is　then　sought　out　by　solving　the　static　equivalent　equations.　It　is　shown　that　the　maximum　error　between　experimental　and　theoretical　results　of　natural　frequency　of　the　rotary　table　is　less　than　3.0%,　thus　the　theoretical　model　is　verified.　The　reactions　between　loads　acting　on　the　axial　rollers　and　radial　rollers　are　negligible.　The　bolt　preloads,　radial　clearance　and　external　load　exert　obvious　effects　on　the　static　stiffness　of　rotary　table　bearing,　and　the　effect　of　external　load　decreases　with　the　increasing　preloads　of　bolts　and　radial　clearance.　©,　Xi＇an　Jiaotong　University.　All　right　reserved.