Solutions　of　inverse　kinematics　is　important　for　a　vertical-six-joint　industrial　robot.　This　paper　proposes　a　method　based　on　the　characteristics　of　the　solutions　and　the　geometric　structure　of　the　robot　to　obtain　proper　inverse　kinematics　solutions　without　calculating　all　sets　of　solutions.　Position　and　orientation　interpolation　are　combined　together　in　curve　interpolation.　The　optimized　solutions　makes　the　robot　move　smoothly　and　avoid　a　sudden　change　in　joint　angles　during　its　trajectory　tracking.　The　experimental　results　verified　the　effectiveness　of　the　proposed　methods　and　showed　that　they　make　the　motion　of　robot　smooth　and　accurate.　©　2013　IEEE.