High-speed　couplings　are　the　key　parts　of　micro-turbomachinerys.　They　are　assembled　to　shafts　by　interference　fits,　which　can　transfer　large　torque,　are　easy　to　produce　and　offer　significant　cost　advantages.　Considering　of　the　influences　of　the　torque,　rotational　speed　and　temperature　variation,　the　interference　fits　between　couplings　and　shafts　have　to　be　analyzed　accurately　in　order　to　save　the　construction　cost　and　reducing　risk　of　invalidation　accidents.　In　this　paper,　a　model　of　the　interference　fit　between　a　coupling　and　a　shaft　is　developed　to　study　the　determine　parameters　of　the　interference　value.　Using　the　classic　elastic　plane　stress　theory,　the　exact　solutions　of　the　radial　stresses,　hoop　stresses　and　radial　displacements　are　obtained.　Three　determine　parameters　(the　torque,　angular　velocity　and　temperature　variation　correction　terms)　are　derived　in　order　to　calculate　the　interference　value.　Taking　a　high-speed　microturbomachinery　for　example,　the　numerical　results　show　that　the　interference　value　is　dependent　of　the　ratios　of　inner　radius　to　outer　radius　of　the　coupling　and　shaft　significantly.　The　torque,　angular　velocity　and　temperature　variation　correction　terms　are　in　the　same　order　of　magnitude.　The　present　analytical　solutions　are　expected　to　be　useful　in　the　structure　design　of　the　interference　fit　between　a　high-speed　coupling　and　a　shaft.