Edge　detection　plays　an　important　role　in　image　processing.　The　classical　gradient　operators　remain　their　few　answers　to　little　marked　edges.　An　improved　edge　detection　method　based　on　maximum　variations　is　presented　in　this　paper.　When　detecting　the　edge,　the　algorithm　enhances　the　variations　at　weak　edge　pixels,　but　doesn＇t　enhance　the　variations　within　an　object.　So　the　algorithm　can　detect　the　little　marked　edges　in　the　image.　The　theory　analysis　and　experiments　also　prove　the　present　algorithm　is　reasonable　and　effective.　©　2011　IEEE.