In　order　to　understand　the　effects　of　a　vertically　incident　CO2　laser　beam　on　the　tungsten-inert　gas　(TIG)　arc　characteristics,　the　spectra　of　the　arc　plasma　with　the　action　of　a　vertically　incident　laser　beam　are　analyzed.　The　electron　temperature　of　the　arc　plasma　is　calculated　by　the　boltzmann　plot　method.　The　results　show　that　the　electron　temperature　of　the　arc　plasma　with　the　action　of　CO2　laser　beam　radiation　is　increased　between　the　laser　acting　position　and　anode　zone.　The　influences　of　laser　power,　arc　current　and　laser　acted　position　on　electron　temperature　are　also　studied.　The　charges　in　electron　temperature　indicate　that　the　inverse　bremsstrahlung　absorption　of　laser　energy　is　the　dominant　factor　influencing　the　electron　temperature　of　TIG　arc　plasma　with　the　action　of　CO2　laser　beam.