Two　kinds　of　auxiliary　templates,　involute　template　and　helix　template,　were　developed　to　remedy　the　shortages　of　Portable　Coordinate　Measuring　Machines　(PCMMs)　in　sampling　strategy　and　evolution　method　for　large　gear　measurement.　By　using　the　templates　to　mark　the　measurement　points　of　tooth　profiles　and　spiral　lines　on　the　gear　flanks,　the　experimental　research　were　performed　on　the　position　repeatability　measurement　of　the　gear.　An　Articulated　Arm　Coordinate　Measuring　Machine　(AACMM)　and　a　Laser　Tracker　Measuring　System　(LTMS)　were　used　to　measure　the　gear　standard　with　an　outside　diameter　of　1　m.　All　the　measurement　data　were　evaluated　by　a　software　INVOLUTE　Pro,　and　the　measurement　uncertainties　of　profile　and　helix　were　obtained.　The　result　demonstrates　that　the　AACMM　is　more　precise　than　LTMS　based　on　above　method　and　the　maximum　deviation　is　8.16　μm　as　compared　to　the　calibration　values.　The　experimental　results　verify　the　validity　and　feasibility　of　the　method,　and　provide　the　basis　for　the　application　of　large　gear　measurement　using　PCMMs.