With　the　development　of　our　society,　the　proportion　of　the　accidents　caused　by　human　behavior　(e.　g.　human　behavior　and　organizational　behavior)　is　increasing　nowadays.　＂Human　Error＂　has　gradually　become　the　focus　of　the　research.　Though　researched　and　confirmed　by　the　experts　home　and　abroad,　the　significance　of　being　the　manager　still　get　overlooked　easily　in　reality.　Taking　into　the　consideration　this　situation,　for　which　authors　propose　＂Condition　Theory＂　and　to　analyze　the　importance　of　the　manager　in　the　security　events　by　telling　examples　to　reach　the　conclusion　that　the　role　of　manager　has　been　the　core　effect　in　the　security　investigation　and　prevention.　(C)　2011　Published　by　Elsevier　Ltd.　Selection　and/or　peer-review　under　responsibility　of　China　Academy　of　Safety　Science　and　Technology,　China　University　of　Mining　and　Technology(Beijing),　McGill　University　and　University　of　Wollongong.