The　distribution　characteristics　of　the　current　density　and　arc　pressure　have　an　important　effect　on　the　welding　process.　Based　on　the　split　anode　method,　the　combined　measurement　system　developed　by　Beijing　University　of　technology　is　used　to　perform　high-accuracy　data　collection　of　arc　current　and　arc　persure.　The　data　is　collected　from　one　of　the　anodes,　and　some　appropriate　processes　are　taken　to　smooth　the　data.　The　distribution　characteristics　of　the　arc　current　density　and　pressure　are　obtained　by　circular　segmentation　calculation.　The　tests　were　carried　out　on　the　DC-TIG　and　DC-plasma　by　the　combined　measurement　system.　The　result　shows　that　the　current　density　and　the　arc　pressure　increase　as　the　current　increasing,　the　area　having　the　higher　current　density　and　arc　pressure　are　also　increasing　slightly;　and　the　diminution　happened　on　the　peak　valuation　of　the　current　density　and　arc　pressure　in　the　centre　while　arc　length　increasing,　meanwhile,　obvious　decrease　can　be　found　in　the　region　where　current　density　and　arc　pressure　are　high　but　the　distribution　radius　of　the　arc　extend;　although　the　arc　pressure　of　the　plasma　arc　is　obviously　larger　than　the　TIG　arc,　there　is　no　evident　impact　on　the　peak　valuation　of　current　density　in　the　end　of　part.　©　2011　IEEE.