The　precision　model　of　the　5-axis　CNC　machine　tool　can　be　built　up　based　on　the　theory　of　kinematics　for　multi-body　system　(MBS).　And　then　based　on　the　precision　model,　the　sensitivity　analysis　established　with　matrix　differential　is　a　method　of　identifying　geometric　error　parameters　for　machine　tool.　And　the　geometric　error　factors　of　major　parts　that　have　relatively　significant　influence　on　comprehensive　spatial　error　of　the　machine　tool　are　identified.　Finally,　important　theoretical　basis　for　improving　the　titanium　alloy　Five-axis　CNC　machining　center　reasonably　and　for　the　error　compensation　can　be　provided.　©　(2013)　Trans　Tech　Publications,　Switzerland.