The　friction　is　a　key　factor　in　metal　forming,　it　comes　into　being　with　the　existence　of　the　contact　surface　between　metal　and　die　which　have　relative　motion.　The　severe　friction　conditions　will　inhibit　the　flow　of　metal,　increase　the　forming　load　significantly　and　increase　the　forming　energy　consumption.　Therefore,　it　has　an　obvious　practical　application　value　of　finding　a　suitable　friction　conditions　in　metal　forming　to　reduce　the　forming　load,　promoting　the　metal　flow,　increasing　the　forming　precision　and　quality　of　the　workpiece,　and　improving　the　die　life.　Currently,　the　finite　element　numerical　simulation　technology　has　been　used　as　an　important　method　to　analyze　the　metal　flow,　the　forming　load　and　the　die　force.　The　friction　criterion　and　its　parameters,　as　one　of　the　important　boundary　condition,　have　got　extensive　attention　and　been　deeply　investigated.　The　friction　factor　and　coefficient　increase　with　the　increasing　of　new　surface　generation　rate　and　contact　pressure,　on　the　basis　of　studying　the　different　friction　experiment　methods.　The　approaches　to　realize　less-loading　is　briefly　introduced　including　metal　surface　treatment　for　improving　friction　conditions,　sheath　extrusion,　vibration　auxiliary　forming.　©　2013　Journal　of　Mechanical　Engineering.