This　article　investigates　the　effects　of　bearing　configuration　on　the　spindle　dynamic　characteristics.　First,　an　analytical　model　of　spindle　is　proposed　and　the　bearing　sets　radial　stiffness　is　calculated.　Second,　the　spindle　analytical　model　is　developed　to　perform　modal　analysis　and　harmonic　response　analysis　with　ANSYS,　and　then　obtain　the　natural　frequency　and　FRF　under　different　bearing　configurations.　The　result　suggests　that　bearing　configuration　has　little　effect　on　the　natural　frequency　of　spindle　system　and　the　FRF　amplitude　corresponding　to　the　1st　natural　frequency　under　back　to　back　configuration　or　face　to　face　configuration　is　relatively　small.　Finally,　the　proposed　model　is　validated　by　modal　experiment.