N-phosphorylamino　acids　can　react　to　form　esters,　peptides,　phosphoryl　ester-exchanged　products　and　phosphoryl　group　migration　products　under　mild　conditions　which　are　very　important　in　researches　on　the　origin　of　life.　It　has　been　proposed　that　the　penta-coordinate　phosphorous　compounds　might　be　the　common　intermediates　of　these　reactions,　which　are　the　key　factor　to　determine　the　activities.　In　this　paper,　the　mechanisms　of　series　reactions　involving　N-phosphorylamino-acids　and　penta-coordinate　phosphorous　compounds　are　studied　with　computational　chemistry　methods.　©　2005　IEEE.