After　the　first　relay　contacts　impact,　they　do　not　reach　the　stable　make　position　at　once,　but　undergo　two　processes-　contact　bounce　and　contact　resistance　transition.　This　paper　presents　an　investigation　of　the　dynamic　contact　characteristics　on　the　NO　and　NC　relay　contacts　which　were　worn　in　different　degrees.　The　results　of　the　experimental　investigation　arc　concludcd　and　analysed.　The　influence　of　the　wear　state　of　the　contact　surface　on　the　dynamic　contact　characteristics　is　discussed.　©　1992　IEEE.