The　striking　arc　of　TIG　touch　was　observed　through　the　spectral　diagnosis　system.　The　changing　phenomenon　of　main　ionized　element　that　provided　the　electrons　in　striking　arc　was　found.　The　metallic　element　was　the　main　contributor　to　provide　the　electrons　at　the　beginning　of　the　discharging,　and　then　the　excited　shielding　gas　element　replaced　the　metallic　element.　The　electron　density　during　the　period　of　the　arc　starting　was　calculated　by　the　Stark-broadened　line　of　Hα.　Through　the　discussion　with　the　repeatability　in　relaxation　phenomenon,　the　statistical　regularity　in　the　arc　starting　process　was　analyzed.　The　similar　rules　as　above　were　observed　via　the　comparison　with　the　laser-assisted　arc　starting　experiments　and　the　MIG　arc　starting　experiments.　It　laid　the　basis　for　further　establishing　the　physical　modeling　in　different　stages　of　the　striking　arc　and　exploration　for　the　new　modes　of　welding　arc　starting.