5A06　aluminum　alloy　sheet　was　welded　by　laser　with　filler　wire.　The　effect　of　welding　parameters,　including　laser　power,　welding　speed　and　filler　wire　speed　on　the　formation　of　joint　was　discussed.　Good　weld　shapes　depended　on　the　welding　process　stability,　which　was　decided　by　optimized　parameters　of　welding　and　filling.　The　defects　of　the　joint　formation　caused　by　the　welding　process　instability　were　analyzed　via　high-speed　video　camera　system.　The　result　indicated　that　the　stable　laser　welding　process　with　filler　wire　could　be　obtained　easily　when　welding　in　preceding　direction,　and　the　distance　between　laser　and　wire　was　controlled　in　the　range　of　0.5-2mm.