Aluminum　alloys　are　among　the　most　important　parts　of　advanced　materials　being　of　strategic　significance.　Laser　beam　welding　is　a　fast　growing　technology　that　offers　new　opportunities　in　the　joining　of　aluminum　alloys.　Alloys　such　as　the　Al　7000　series　that　are　unweldable　with　conventional　techniques　are　readily　joined　by　laser　welding　to　produce　welds　with　high　strength.　However,　the　high　reflectivity,　the　high　thermal　conductivity,　the　high　fluidity,　the　high　chemical　reactivity　as　well　as　the　low　ionization　energy　of　Al　element　make　the　physical　processes　complex　in　laser　welding　of　aluminum　and　its　alloys.　In　this　paper,　the　key　scientific　problems　and　issues　are　reviewed　and　some　novel　processes　and　techniques　are　introduced　mainly　based　on　the　author＇s　research　achievements　financially　supported　by　the　＇863　Program＇　of　the　Ministry　of　Science　and　Technology　of　China,　the　Program　for　New　Century　Excellent　Talents　in　University　of　the　Ministry　of　Education　of　China　and　other　programs.