This　paper　proposes　a　thermo-mechanical　error　model　of　a　hydrostatic　spindle　for　a　high　precision　machine　tool.　By　predicting　the　variation　of　motion　error　induced　by　thermal　effects　on　a　machine　work-table　during　machining,　this　model　allows　deeper　insights　into　the　underlying　mechanisms　that　result　in　evolutions　of　the　spindle　accuracy.　The　heat　power　generated　in　the　spindle　elements　and　the　coefficients　of　convection　heat　transfer　over　its　outer　surface　have　been　evaluated.　Then,　the　distribution　of　temperature　and　deformation　of　the　spindle　have　been　simulated　by　a　finite　element　coupled　thermo-elastic　model,　from　which　the　influence　on　notably　spindle　stiffness　variation　was　deduced.　Experimental　measurement　of　the　thrust　plate　axial　displacement　under　thermal　expansion　is　in　close　agreement　with　the　computed　axial　thermal　expansion.　(C)　2011　Elsevier　Inc.　All　rights　reserved.