The　quality　of　high　speed　machining　is　directly　related　to　dynamic　characteristics　of　spindle-toolholder　interface.　The　paper　established　normal　and　tangential　interactions　of　BT　spindle-toolholder　interface　based　on　finite　element　contact　theory,　and　analysed　free　modal　in　Abaqus/Standard.　Then　the　result　was　compared　with　the　experimental　modal　analysis.　It　shows　that　the　finite　element　model　is　effective　and　could　be　applied　in　the　future　dynamic　study　of　high-speed　spindle　system.