Laser-arc　hybrid　welding　is　a　promising　technology　which　can　be　widely　used　in　industry　and　it　attracts　attention　of　the　researchers　worldwide.　Combining　two　heat　sources　with　different　physical　properties　and　energy　transmission　mechanisms　together,　laser-arc　hybrid　welding　possesses　the　composite　advantages　of　laser　welding　and　arc　welding.　In　this　article,　a　review　of　the　fundamental　phenomenon　such　as　arc　and　beam　characteristics　and　laser-arc　interaction　when　a　CO2　and　YAG　laser　beam　interacts　with　arc　plasma　are　presented.　Integrated　with　the　current　work　of　authors,　a　few　new　developed　practical　applications　of　hybrid　welding　are　described.　Finally,　a　section　is　devoted　to　explain　about　further　work　required　in　order　to　understand　and　expand　the　application　of　the　hybrid　welding　process　in　the　future.